KT Corp

KT Corporation and Subsidiaries Condensed Consolidated Interim Financial Statements June 30, 2026 and 2025 (Unaudited), and December 31, 2025 ATTACHMENT : INDEPENDENT AUDITOR'S REVIEW REPORT

KT Corporation and Subsidiaries Index June 30, 2026 and 2025, and December 31, 2025 Page(s) Report on Review of Condensed Consolidated Interim Financial Statements ... 1 - 2 Condensed Consolidated Interim Financial Statements Condensed Consolidated Interim Statements of Financial Position…………………… 3 - 4 Condensed Consolidated Interim Statements of Profit or Loss………………………… 5 Condensed Consolidated Interim Statements of Comprehensive Income …………… 6 Condensed Consolidated Interim Statements of Changes in Equity ……………… 7 - 8 Condensed Consolidated Interim Statements of Cash Flows ………………………. 9 - 10 Notes to the Condensed Consolidated Interim Financial Statements ………………… 11 - 70

Report on Review of Condensed Consolidated Interim Financial Statements (English Translation of a Report Originally Issued in Korean) To the Shareholders and Board of Directors of KT Corporation Reviewed Financial Statements We have reviewed the accompanying condensed consolidated interim financial statements of KT Corporation and its subsidiaries (collectively referred to as the "Group"). These condensed consolidated interim financial statements consist of the consolidated interim statement of financial position of the Group as at June 30, 2026, and the related consolidated interim statements of profit or loss and comprehensive income for the three-month and six-month periods ended June 30, 2026, and the related consolidated interim statements of changes in equity and cash flows for the six-month period ended June 30, 2026, and material accounting policy information and other selected explanatory notes, expressed in Korean won. Management's Responsibility for the Financial Statements Management is responsible for the preparation and presentation of these condensed consolidated interim financial statements in accordance with International Financial Reporting Standards as adopted by the Republic of Korea (Korean IFRS) 1034 Interim Financial Reporting, and for such internal control as management determines is necessary to enable the preparation of condensed consolidated interim financial statements that are free from material misstatement, whether due to fraud or error. Auditor's Responsibility Our responsibility is to express a conclusion on these condensed consolidated interim financial statements based on our review. We conducted our review in accordance with quarterly or semi-annual review standards established by the Securities and Futures Commission of the Republic of Korea. A review of interim financial information consists of making inquiries, primarily of persons responsible for financial and accounting matters, and applying analytical and other review procedures. A review is substantially less in scope than an audit conducted in accordance with Korean Standards on Auditing and consequently does not enable us to obtain assurance that we would become aware of all significant matters that might be identified in an audit. Accordingly, we do not express an audit opinion. Conclusion Based on our review, nothing has come to our attention that causes us to believe the accompanying condensed consolidated interim financial statements are not prepared, in all material respects, in accordance with Korean IFRS 1034 Interim Financial Reporting.

2 Other Matters The consolidated interim statements of profit or loss and comprehensive income for the three-month and six-month periods ended June 30, 2025, and the consolidated interim statements of changes in equity and cash flows for the six-month period ended June 30, 2025, presented herein for comparative purposes, were reviewed by Deloitte Anjin LLC whose report dated August 14, 2025. Based on their review, nothing has come to their attention that causes them to believe the accompanying consolidated interim financial statements do not present fairly, in all material respects, in accordance with Korean IFRS 1034 Interim Financial Reporting. The consolidated statement of financial position as at December 31, 2025, and the consolidated statements of profit or loss, comprehensive income, changes in equity and cash flows for the year then ended, not presented herein, were audited by Deloitte Anjin LLC who expressed an unqualified opinion on those statements on March 13, 2026. The consolidated statement of financial position as at December 31, 2025, presented herein for comparative purposes, is consistent, in all material respects, with the above audited consolidated statement of financial position as at December 31, 2025. Review standards and their application in practice vary among countries. The procedures and practices used in the Republic of Korea to review such financial statements may differ from those generally accepted and applied in other countries. August 14, 2026 Seoul, Korea This report is effective as of August 14, 2026, the review report date. Certain subsequent events or circumstances, which may occur between the review report date and the time of reading this report, could have a material impact on the accompanying condensed consolidated interim financial statements and notes thereto. Accordingly, the readers of the review report should understand that there is a possibility that the above review report may have to be revised to reflect the impact of such subsequent events or circumstances, if any.

KT Corporation and Subsidiaries Condensed Consolidated Interim Statements of Financial Position As at June 30, 2026 and December 31, 2025 (in millions of Korean won) Notes Assets Current assets Cash and cash equivalents 4,30 ₩ 3,049,813 ₩ 3,506,971 Trade and other receivables, net 4,5,30 6,353,804 5,845,149 Other financial assets 4,6,30 2,170,061 1,626,982 Current tax assets 1,653 9,875 Inventories, net 7 625,658 416,135 Current assets held-for-sale 9 2,426 4,316 Other current assets 8 2,618,187 2,568,108 Total current assets 14,821,602 13,977,536 Non-current assets Trade and other receivables, net 4,5,30 2,168,045 2,069,139 Other financial assets 4,6,30 4,227,939 3,362,916 Property and equipment, net 10 13,695,926 14,258,472 Right-of-use assets 17 1,446,287 1,538,117 Investment properties, net 10 2,999,847 2,872,049 Intangible assets, net 10 1,873,981 1,556,621 Investments in associates and joint ventures 11 1,625,339 1,563,946 Deferred tax assets 669,006 660,107 Net defined benefit assets 15 49,441 71,840 Other non-current assets 8 1,107,635 1,017,830 Total non-current assets 29,863,446 28,971,037 Total assets ₩ 44,685,048 ₩ 42,948,573 June 30, 2026 December 31, 2025 3

KT Corporation and Subsidiaries Condensed Consolidated Interim Statements of Financial Position As at June 30, 2026 and December 31, 2025 (in millions of Korean won) Notes Liabilities Current liabilities Trade and other payables 4,12,30 ₩ 6,781,293 ₩ 6,868,707 Borrowings 4,13,30 4,179,481 2,499,539 Other financial liabilities 4,6,30 442,817 526,093 Current tax liabilities 286,450 237,613 Provisions 14,16 274,947 312,811 Deferred income 20 64,525 62,175 Other current liabilities 4,8,17 1,132,950 1,185,826 Total current liabilities 13,162,463 11,692,764 Non-current liabilities Trade and other payables 4,12,30 613,499 328,269 Borrowings 4,13,30 7,091,342 8,286,033 Other financial liabilities 4,6,30 585,479 592,599 Net defined benefit liabilities 15 153,783 85,631 Provisions 14 102,225 105,074 Deferred income 20 134,142 140,615 Deferred tax liabilities 1,375,203 1,151,424 Other non-current liabilities 4,8,17 1,035,627 1,108,141 Total non-current liabilities 11,091,300 11,797,786 Total liabilities 24,253,763 23,490,550 Equity attribute to owners of the Controlling Company Share capital 1,564,499 1,564,499 Share premium 1,440,258 1,440,258 Retained earnings 18 15,469,964 14,964,332 Accumulated other comprehensive income 1,139,151 563,279 Other components of equity 19 (1,029,461) (876,715) 18,584,411 17,655,653 Non-controlling interest 1,846,874 1,802,370 Total equity 20,431,285 19,458,023 Total liabilities and equity ₩ 44,685,048 ₩ 42,948,573 The above consolidated interim statements of financial position should be read in conjunction with the accompanying notes. June 30, 2026 December 31, 2025 4

KT Corporation and Subsidiaries Condensed Consolidated Interim Statements of Profit or Loss For the three-month and six-month periods ended June 30, 2026 and 2025 (in millions of Korean won, except per share amounts) Notes Operating revenue 20,28 ₩ 6,679,866 ₩ 13,458,314 ₩ 7,427,337 ₩ 14,272,454 Operating expenses 21 6,031,551 12,327,298 6,412,519 12,568,865 Operating profit 28 648,315 1,131,016 1,014,818 1,703,589 Other income 22 74,926 171,290 9,284 74,646 Other expenses 22 106,355 164,055 36,101 73,911 Finance income 23 175,472 440,791 348,136 476,230 Finance costs 23 174,531 455,569 376,947 501,306 Share of net profits of associates and joint ventures 11 28,259 35,150 15,739 7,511 646,086 1,158,623 974,929 1,686,759 Income tax expense 24 165,550 289,766 241,647 386,678 ₩ 480,536 ₩ 868,857 ₩ 733,282 ₩ 1,300,081 Profit for the Year Attributable to: Owners of the Parent Company ₩ 440,083 ₩ 792,330 ₩ 687,941 ₩ 1,227,780 Non-controlling interests 40,453 76,527 45,341 72,301 Earnings per share attributable to the equity holders of the Parent Company Basic earnings per share 25 ₩ 1,830 ₩ 3,290 ₩ 2,820 ₩ 5,014 Diluted earnings per share 25 1,829 3,287 2,819 5,010 The above consolidated interim statements of profit or loss should be read in conjunction with the accompanying notes. Profit before Income Tax Profit for the period during the period (in Korean won): Three-Month and Six-Month Periods Ended June 30 2026 2025 Three-month Six-month Three-month Six-month 5

KT Corporation and Subsidiaries Condensed Consolidated Interim Statements of Comprehensive Income For the three-month and six-month periods ended June 30, 2026 and 2025 (in millions of Korean won) Notes Profit for the period ₩ 480,536 ₩ 868,857 ₩ 733,282 ₩ 1,300,081 Other comprehensive income (loss) Items that will not be reclassified to profit or loss: Remeasurements of the net defined benefit liabilities 15 2,185 (258) 4,780 918 (70) (93) 112 256 6 257,893 579,690 153,099 146,427 Items that are or may be subsequently reclassified to profit or loss: (42) (164) - - Valuation gains (losses) on cash flow hedges 6 38,432 166,576 (184,101) (170,278) (41,419) (160,354) 185,928 186,968 (4,253) (13,940) 4,857 5,638 Exchange differences on translation of foreign operations 3,120 (905) (38,414) (36,682) 255,846 570,552 126,261 133,247 Total comprehensive income for the period ₩ 736,382 ₩ 1,439,409 ₩ 859,543 ₩ 1,433,328 Total comprehensive income for the period attributable to: Owners of the Parent Company ₩ 696,371 ₩ 1,370,116 ₩ 826,274 ₩ 1,382,296 Non-controlling interests 40,011 69,293 33,269 51,032 Three-month Six-month Three-month Six-month The above consolidated interim statements of comprehensive income should be read in conjunction with the accompanying notes. Share of remeasurement of the net defined benefit liabilities of associates and joint ventures Other comprehensive income (loss) from cash flow hedges reclassified to profit or loss Share of other comprehensive income (loss) of associates and joint ventures Other comprehensive income for the period, net of tax Valuation gains on equity instruments at fair value through other comprehensive income Loss on valuation of debt instruments at fair value through other comprehensive income Three-Month and Six-Month Periods Ended June 30 2026 2025 6

KT Corporation and Subsidiaries Condensed Consolidated Interim Statements of Changes in Equity For the six-month periods ended June 30, 2026 and 2025 (in millions of Korean won) Share Notes capital Balance at January 1, 2025 ₩ 1,564,499 ₩ 1,440,258 ₩ 13,779,776 ₩ 63,729 ₩ (637,560) ₩ 16,210,702 ₩ 1,785,847 ₩ 17,996,549 Comprehensive income Profit for the period - - 1,227,780 - - 1,227,780 72,301 1,300,081 Remeasurements of net defined benefit liabilities 15 - - 857 - - 857 61 918 Share of remeasurement of the net defined benefit liabilities of associates and joint ventures - - 261 - - 261 (5) 256 Share of other comprehensive income of associates and joint ventures - - - 5,630 - 5,630 8 5,638 Valuation gains (losses) on cash flow hedges 6 - - - 16,709 - 16,709 (19) 16,690 Valuation gains (losses) on financial instruments at fair value through other comprehensive income 6 - - 1,089 145,946 - 147,035 (608) 146,427 Exchange differences on translation of foreign operations - - - (15,976) - (15,976) (20,706) (36,682) Total comprehensive income for the period - - 1,229,987 152,309 - 1,382,296 51,032 1,433,328 Transactions with owners Dividends paid by the Parent Company - - (122,836) - - (122,836) - (122,836) Interim dividends paid by the Parent Company - - (146,984) - - (146,984) - (146,984) Dividends paid to non-controlling interest of subsidiaries - - - - - - (18,572) (18,572) Change in consolidation scope - - - - - - (60,177) (60,177) Change in ownership interests in subsidiaries - - - - 804 804 (7,242) (6,438) Appropriation of retained earnings related to loss on disposal of treasury stock - - (57) - 57 - - - Acquisition of treasury stock - - - - (199,374) (199,374) - (199,374) Disposal of treasury stock - - - - 4,075 4,075 - 4,075 Others - - - - (4,847) (4,847) 2,394 (2,453) Subtotal - - (269,877) - (199,285) (469,162) (83,597) (552,759) Balance at June 30, 2025 ₩ 1,564,499 ₩ 1,440,258 ₩ 14,739,886 ₩ 216,038 ₩ (836,845) ₩ 17,123,836 ₩ 1,753,282 ₩ 18,877,118 premium earnings income of equity Total Non-controlling Total interest equity Share Retained other comprehensive components Attributable to owners of the Controlling Company Accumulated Other 7

KT Corporation and Subsidiaries Condensed Consolidated Interim Statements of Changes in Equity For the six-month periods ended June 30, 2026 and 2025 (in millions of Korean won) Notes Balance at January 1, 2026 ₩ 1,564,499 ₩ 1,440,258 ₩ 14,964,332 ₩ 563,279 ₩ (876,715) ₩ 17,655,653 ₩ 1,802,370 ₩ 19,458,023 Comprehensive income Profit for the year - - 792,330 - - 792,330 76,527 868,857 Remeasurements of net defined benefit liabilities 15 - - (2,082) - - (2,082) 1,824 (258) Share of remeasurement of the net defined benefit liabilities of associates and joint ventures - - (97) - - (97) 4 (93) Share of other comprehensive income of associates and joint ventures - - - (10,988) - (10,988) (2,952) (13,940) Valuation gains on cash flow hedges 6 - - - 5,944 - 5,944 278 6,222 Valuation gains (losses) on financial instruments at fair value through other comprehensive income 6 - - 4,093 578,649 - 582,742 (3,216) 579,526 Exchange differences on translation of foreign operations - - - 2,267 - 2,267 (3,172) (905) Total comprehensive income for the period - - 794,244 575,872 - 1,370,116 69,293 1,439,409 Transactions with owners Dividends paid by the Parent Company - - (144,658) - - (144,658) - (144,658) Interim dividends paid by the Parent Company - - (143,863) - - (143,863) - (143,863) Dividends paid to non-controlling interest of subsidiaries - - - - - - (26,223) (26,223) Change in ownership interests in subsidiaries - - - - (1,305) (1,305) (312) (1,617) Appropriation of retained earnings related to - - (91) - 91 - - - Acquisition of treasury stock - - - - (153,560) (153,560) - (153,560) Disposal of treasury stock - - - - 4,716 4,716 - 4,716 Others - - - - (2,688) (2,688) 1,746 (942) Subtotal - - (288,612) - (152,746) (441,358) (24,789) (466,147) Balance at June 30, 2026 ₩ 1,564,499 ₩ 1,440,258 ₩ 15,469,964 ₩ 1,139,151 ₩ (1,029,461) ₩ 18,584,411 ₩ 1,846,874 ₩ 20,431,285 The above consolidated Interim statements of changes in equity should be read in conjunction with the accompanying notes. Total interest equity Share Share Retained other comprehensive components capital premium earnings income of equity Other Non-controlling Total Attributable to owners of the Controlling Company Accumulated 8

KT Corporation and Subsidiaries Condensed Consolidated Interim Statements of Cash Flows For the six-month periods ended June 30, 2026 and 2025 (in millions of Korean won) Notes Cash flows from (used in) operating activities Cash generated from operations 26 ₩ 2,325,675 ₩ 2,793,143 Interest paid (222,585) (204,874) Interest received 177,178 176,611 Dividends received 62,564 41,793 Income tax paid (171,208) (120,385) Cash flows from operating activities 2,171,624 2,686,288 Cash flows from (used in) investing activities Collection of loans 18,866 17,418 Disposals of financial assets at fair value through profit or loss 49,725 50,505 Disposal of financial assets at amortized cost 1,013,328 428,377 13,605 2,297 1,860 - 5,011 13,205 Disposals of property, equipment and investment properties 23,301 30,534 Disposals of intangible assets 312 3,128 Disposals of right-of-use assets 324 423 Disposals of derivatives 981 4,256 Increase in cash due to change in consolidation scope - 126,968 Loans granted (7,087) (33,073) Acquisitions of financial assets at fair value through profit or loss (60,826) (39,953) Acquisitions of financial assets at amortized cost (1,205,883) (532,341) Acquisitions of financial assets at fair value through other comprehensive income (3,328) (100,000) Acquisitions of investments in associates and joint ventures (25,780) (13,942) Acquisitions of property and equipment and investment properties (1,184,005) (2,029,371) Acquisitions of intangible assets (491,275) (345,943) Acquisitions of right-of-use assets (27) (169) Decrease in cash due to consolidation scope change - (3) Cash outflow under derivatives contracts (109,960) - Cash flows used in investing activities ₩ (1,960,858) ₩ (2,417,684) Six-Month Periods Ended June 30 2026 2025 Disposals of financial assets at fair value through other comprehensive income Disposals of investments in associates and joint ventures Disposals of assets held-for-sale 9

KT Corporation and Subsidiaries Condensed Consolidated Interim Statements of Cash Flows For the six-month periods ended June 30, 2026 and 2025 (In millions of Korean won) Notes Cash flows from (used in) financing activities 27 Proceeds from borrowings ₩ 1,666,206 ₩ 3,651,239 Cash inflow from derivatives contracts - 405 Cash inflow from transactions with non-controlling shareholders 383 482 Cash inflow from other financing activities 34 26,583 Repayments of borrowings (1,650,755) (3,166,955) Dividends paid (314,744) (288,392) Decrease in lease liabilities (217,199) (202,157) Cash outflow under derivatives contracts - (3,724) Acquisition of treasury stock (153,560) (199,374) Cash outflow from transactions with non-controlling shareholders (2,001) (3,634) Cash outflow from other financing activities (484) (663) Cash flows used in financing activities (672,120) (186,190) Effect of exchange rate change on cash and cash equivalents 4,196 (4,684) Net increase (decrease) in cash and cash equivalents (457,158) 77,730 Cash and cash equivalents Beginning of the period 3,506,971 3,716,680 End of the period ₩ 3,049,813 ₩ 3,794,410 The above consolidated Interim statements of cash flows should be read in conjunction with the accompanying notes. 2026 2025 Six-Month Periods Ended June 30 10

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited), and December 31, 2025 11 1. General Information The consolidated financial statements have been prepared by KT Corporation, the "Controlling Company" as defined under Korean IFRS 1110 Consolidated Financial Statements, by consolidating 78 subsidiaries (collectively referred to as the "Group") including BC Card Co., Ltd. and othersas described in Note 1.2 1.1 The Controlling Company KT Corporation (the "Controlling Company") commenced operations on January 1, 1982, when it spun off from the Korea Communications Commission (formerly the Korean Ministry of Information and Communications) to provide telecommunication services and to engage in the development of advanced communications services under the Act of Telecommunications of Korea. The address of the Controlling Company's registered office is 90, Buljeong-ro, Bundang-gu, Seongnam-si, Gyeonggi-do, Republic of Korea. On October 1, 1997, upon the announcement of the Act on the Management of Government-Invested Institutions and the Privatization Law, the Controlling Company became a government-funded institution under the Commercial Code of Korea. On December 23, 1998, the Controlling Company's shares were listed on the Korea Exchange. On May 29, 1999, the Controlling Company issued 24,282,195 additional shares and issued American Depository Shares (ADS), which represented new shares and 20,813,311 government-owned shares, on the New York Stock Exchange. On July 2, 2001, additional ADS representing 55,502,161 government-owned shares were issued on the New York Stock Exchange. In 2002, the Controlling Company acquired the entire government-owned shares in accordance with the Korean government's privatization plan. As at June 30, 2026, the Korean government does not own any shares in the Controlling Company.

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited), and December 31, 2025 12 1.2 Consolidated Subsidiaries (1) The consolidated subsidiaries as at June 30, 2026 and December 31, 2025, are as follows: Controlling Interest 1 (%) Subsidiary Type of business Location June 30, 2026 December 31, 2025 Closing month KT Telecop Co., Ltd. Security service Korea 92.7% 92.7% December KT Alpha Co., Ltd. 4 Data communication Korea 73.0% 73.0% December KT Service Bukbu Co., Ltd. Opening services of fixed line Korea 78.9% 78.9% December KT Service Nambu Co., Ltd. 4 Opening services of fixed line Korea 97.8% 97.8% December KT Commerce Inc. B2C, B2B service and relevant value-added service Korea 100.0% 100.0% December KT Strategic Investment Fund No.3 Investment fund Korea 100.0% 100.0% December KT Strategic Investment Fund No.4 Investment fund Korea 100.0% 100.0% December KT Strategic Investment Fund No.5 Investment fund Korea 100.0% 100.0% December BC-VP Strategic Investment Fund No.1 Investment fund Korea 100.0% 100.0% December BC Card Co., Ltd. Credit card business Korea 69.5% 69.5% December VP Inc. 4 Payment security service for credit card, others Korea 72.2% 72.2% December BC Card China Co., Ltd. Software development and data processing China 100.0% 100.0% December Smartro Co., Ltd. VAN (Value Added Network) business Korea 64.5% 64.5% December KTDS Co., Ltd. 4 System integration and maintenance Korea 91.6% 91.6% December KT M&S Co., Ltd. PCS distribution Korea 100.0% 100.0% December KT GENIE Music Corporation2 Online music production and distribution Korea 36.0% 36.0% December KT MOS Bukbu Co., Ltd. 4 Telecommunication facility maintenance Korea 100.0% 100.0% December KT MOS Nambu Co., Ltd. 4 Telecommunication facility maintenance Korea 98.4% 98.4% December KT Skylife Co., Ltd. 4 Satellite TV Korea 50.5% 50.5% December KT ENA Co., Ltd. TV contents provider Korea 100.0% 100.0% December KT Estate Inc. Residential building development and supply Korea 100.0% 100.0% December KT Investment Management Inc. Asset management, real estate, and consulting services Korea 100.0% 100.0% December KTGDH Co., Ltd. Data center development and related service Korea 100.0% 100.0% December KT Sat Co., Ltd. Satellite communication business Korea 100.0% 100.0% December kt Nasmedia Co., Ltd.2,4 Solution provider and IPTV advertisement sales business Korea 44.7% 44.1% December KT Sports Co., Ltd. Management of sports teams Korea 100.0% 100.0% December KTCS Corporation 2,4 Database and online information provider Korea 34.1% 34.1% December KTIS Corporation 2,4 Database and online information provider Korea 33.4% 33.4% December KT M Mobile Co., Ltd. Special category telecommunications operator and sales of communication device Korea 100.0% 100.0% December

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited), and December 31, 2025 13 Controlling Interest 1 (%) Subsidiary Type of business Location June 30, 2026 December 31, 2025 Closing month KT Investment Co., Ltd. Financing business for new technology Korea 100.0% 100.0% December Next Connect PFV Co., Ltd. Residential building development and supply Korea 100.0% 100.0% December KT Rwanda Networks Ltd. Network install management Rwanda 51.0% 51.0% December AOS Ltd. System integration and maintenance Rwanda 51.0% 51.0% December KT Japan Co., Ltd. Foreign investment business and local counter work Japan 100.0% 100.0% December East Telecom LLC Wireless/fixed line internet business Uzbekistan 91.6% 91.6% December KT America, Inc. Foreign investment business and local counter work USA 100.0% 100.0% December PT. BC Card Asia Pacific Software development and delivery Indonesia 99.9% 99.9% December KT Hongkong Telecommunications Co., Ltd. Fixed line telecommunication business Hong Kong 100.0% 100.0% December Korea Telecom Singapore Pte. Ltd. Foreign investment business and local counter work Singapore 100.0% 100.0% December Texnoprosistem LLC Fixed line internet business Uzbekistan 100.0% 100.0% December KT Huimangjieum Co., Ltd. Manufacturing Korea 100.0% 100.0% December K-REALTY RENTAL HOUSING REIT 3 Residential building Korea 88.6% 88.6% December Storywiz Co., Ltd. Contents and software development and supply Korea - 100.0% December KT Engineering Co., Ltd. Telecommunication facility construction and maintenance Korea 100.0% 100.0% December KT Studio Genie Co., Ltd. Data communication service and data communication construction business Korea 90.9% 90.9% December KTHS Corporation Operation and maintenance of facilities Korea 100.0% 100.0% December kt HCN Co., Ltd. Cable television service Korea 100.0% 100.0% December kt Millie Seojae 2 Book contents service Korea 38.4% 38.4% December KT ES Pte. Ltd. Foreign investment business Singapore 68.8% 68.8% December Epsilon Global Communications PTE. Ltd. Network service industry Singapore 100.0% 100.0% December Epsilon Telecommunications (SP) PTE. Ltd. Fixed line telecommunication business Singapore 100.0% 100.0% December Epsilon Telecommunications (US) PTE. Ltd. Fixed line telecommunication business Singapore 100.0% 100.0% December Epsilon Telecommunications Limited Fixed line telecommunication business UK 100.0% 100.0% December Epsilon Telecommunications (HK) Limited Fixed line telecommunication business Hong Kong 100.0% 100.0% December Epsilon US Inc. Fixed line telecommunication business USA 100.0% 100.0% December Epsilon Telecommunications (BG) EOOD Employee support service Bulgaria 100.0% 100.0% December Nasmedia-KT Alpha Future Growth Strategic Investment Fund Investment fund Korea 100.0% 100.0% December KT Strategic Investment Fund 6 Investment fund Korea 100.0% 100.0% December

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited), and December 31, 2025 14 Controlling Interest 1 (%) Subsidiary Type of business Location June 30, 2026 December 31, 2025 Closing month KT Altimedia Corporation Software development and delivery Korea 100.0% 100.0% December KT Altimedia B.V. Software development and delivery Netherlands 100.0% 100.0% December KT Altimedia Vietnam Software development and delivery Vietnam 100.0% 100.0% December BCCARD VIETNAM LTD. Software sales business Vietnam 100.0% 100.0% December KTP SERVICES INC. Fixed line telecommunication business Philippines 100.0% 100.0% December Hangang Real Estate Investment Trust No. 24 Investment fund Korea 75.0% 75.0% December KT DX VIETNAM COMPANY LIMITED Software development Vietnam 100.0% 100.0% December KT Cloud Co., Ltd. Information and communications development Korea 92.6% 92.6% December PT CRANIUM ROYAL ADITAMA Software development Indonesia 67.0% 67.0% December Open cloud lab Co., Ltd. IT consulting service and Telecommunication equipment sales Korea 100.0% 100.0% December KT Living, Inc. Residential building management Korea 100.0% 100.0% December K-Realty Qualified Private Real Estate Investment Trust No. 1 3 Real estate management Korea 6.5% 6.5% December AQUA RETAIL VIETNAM COMPANY LIMITED E-voucher issuance and trading business Vietnam 100.0% 100.0% December K-Realty Qualified Private Real Estate Investment Trust No. 4 Real estate management Korea 98.3% 98.3% December BC Strategic Investment Fund 2 Investment fund Korea 100.0% 100.0% December K-Logis Hwaseong Inc. Residential building development and supply Korea 80.0% 80.0% December kt netcore Co. Ltd. Telecommunication facility maintenance and service business Korea 100.0% 100.0% December kt p&m Co. Ltd. Information and communications development and electrical engineering construction Korea 100.0% 100.0% December Seongsu269 Development PFV Co, Ltd Investment fund Korea 90.9% 85.2% December Gangnam Station 1307 PFV Co., Ltd. Investment fund Korea 60.3% 60.3% December AI Media Broadcasting Co., Ltd. Satellite TV Korea 100% - December 1 Sum of the interests owned by the Controlling Company and subsidiaries. 2 Although the Controlling Company owns less than 50% of the interest in kt Nasmedia Co., Ltd., KTCS Corporation, KTIS Corporation, kt Millie Seojae, and KT GENIE Music Corporation, these entities are consolidated as the Controlling Company can exercise the majority of voting rights in its decision-making process at all times, based on voting patterns at previous shareholders' meetings. 3 Although the Controlling Company owns less than 50% of the interest in K-Realty Qualified Private Real Estate Investment Trust No. 1, this entity is consolidated by comprehensively considering the criteria for determining control, such as 'power', 'variable profit', and 'relationship between power and variable profit', rather than simply judging by the interests owned by the Controlling Company. 4 The number of treasury stock held by subsidiaries are deducted from the total number of shares when calculating the controlling percentage interest.

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited), and December 31, 2025 16 (In millions of Korean won) June 30, 2026 Six-month period ended June 30, 2026 ss Total assets Total liabilities Operating revenues Profit(loss) for the period KT Studio Genie Co., Ltd. 1 795,082 181,712 254,103 4,962 East Telecom LLC 1 95,511 39,799 19,418 2,482 KT ES Pte. Ltd. 1 77,749 76,934 53,202 (7,627) KTP SERVICES INC. 2,115 18 42 (137) KT Altimedia Corporation 1 39,984 7,595 16,732 94 KT DX VIETNAM COMPANY LIMITED 1,300 124 602 (76) KT Cloud Co., Ltd. 1 2,645,455 1,070,278 515,513 12,740 K-Realty Qualified Private Real Estate Investment Trust No. 1 77,176 50,381 2,299 (128) AQUA RETAIL VIETNAM COMPANY LIMITED 317 - - - kt netcore. Co. Ltd. 171,851 107,059 317,389 23 kt p&m Co. Ltd. 33,514 18,563 35,086 2,335 1 As intermediate controlling companies, financial information from their consolidated financial statements is presented. 2 Redeemable preferred stock issued by subsidiaries as at the end of the reporting period is included in liabilities. (In millions of Korean won) December 31, 2025 Six-month period ended June 30, 2025 ss Total assets Total liabilities Operating revenues Profit(loss) for the period KT Telecop Co., Ltd. ₩ 393,333 234,285 293,735 11,369 KT Alpha Co., Ltd. 495,896 192,822 196,613 24,085 KT Service Bukbu Co., Ltd. 59,502 53,859 112,545 (1,092) KT Service Nambu Co., Ltd. 107,727 99,990 185,107 (10,750) BC Card Co., Ltd. 1 6,558,304 4,626,053 1,781,787 94,873 KT Nasmedia Co., Ltd.1 440,266 238,576 57,429 2,494 KTDS Co., Ltd. 1 311,710 146,073 327,172 16,937 KT M&S Co., Ltd. 238,108 157,783 364,500 11,081 KT MOS Bukbu Co., Ltd. 54,039 34,830 48,748 368 KT MOS Nambu Co., Ltd. 54,657 29,236 49,280 933 KT Skylife Co., Ltd. 1 975,400 413,080 490,091 12,559 KT Estate Inc. 1 3,266,800 1,534,793 294,380 3,029 KT GDH Co., Ltd. 7,852 1,181 1,693 131 KT Sat Co., Ltd. 696,796 32,436 93,191 15,090 KT Sports Co., Ltd. 32,098 7,205 49,436 6,129

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited), and December 31, 2025 17 (In millions of Korean won) December 31, 2025 Six-month period ended June 30, 2025 ss Total assets Total liabilities Operating revenues Profit(loss) for the period KT M Mobile Co., Ltd. 222,683 90,445 191,733 7,521 KT Investment Co., Ltd. 1 73,066 43,133 2,797 539 KTCS Corporation 1 470,973 245,806 483,248 15,325 KTIS Corporation 449,527 211,060 309,309 10,068 Next Connect PFV 967,898 279,246 1,040,417 360,097 KT Japan Co., Ltd. 1 1,900 3,271 1,642 89 KT America, Inc. 7,080 589 3,788 152 KT Rwanda Networks Ltd. 2 112,981 149,440 10,409 (10,938) AOS Ltd. 2 17,996 20,221 5,792 1,236 KT Hong Kong Telecommunications Co., Ltd. 9,942 2,202 5,882 202 KT Huimangjieum 1 11,134 3,408 9,351 367 KT Engineering Co., Ltd. 153,146 95,252 90,953 (8,526) KT Studio Genie Co., Ltd. 1 791,790 181,688 229,742 9,879 East Telecom LLC 1 88,259 39,227 20,584 5,344 KT ES Pte. Ltd. 1 76,013 69,059 48,590 967 KTP SERVICES INC. 2,179 10 - (129) KT Altimedia Corporation 1 42,655 9,300 16,801 193 KT DX VIETNAM COMPANY LIMITED 1,457 291 356 (134) KT Cloud Co., Ltd. 1 2,659,479 1,099,355 470,610 36,442 K-Realty Qualified Private Real Estate Investment Trust No. 1 77,384 50,062 2,276 (618) AQUA RETAIL VIETNAM COMPANY LIMITED 296 - 501 (422) kt netcore. Co. Ltd. 174,021 109,253 269,107 (17,821) kt p&m Co. Ltd. 32,513 19,889 31,834 1,016 1 As intermediate controlling companies, financial information from their consolidated financial statements is presented. 2 Redeemable preferred stock issued by subsidiaries as at the end of the reporting period is included in liabilities.

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 18 2. Material Accounting Policies 2.1 Basis of Preparation The Group maintains its accounting records in Korean won and prepares statutory financial statements in the Korean language (Hangeul) in accordance with International Financial Reporting Standards as adopted by the Republic of Korea (K-IFRS). The accompanying consolidated financial statements have been condensed, reformatted, and translated into English from the original Korean language financial statements. The consolidated interim financial statements of the Group for the six-month period ended June 30, 2026, have been prepared in accordance with Korean IFRS 1034 Interim Financial Reporting. In order to understand the consolidated interim financial statements, the annual consolidated financial statements as at December 31, 2025 prepared in accordance with IFRS should be used together. 2.2 Changes in Accounting Policy and Disclosures (1) New and amended standards and interpretations adopted by the Group The Group has applied the following standards and amendments for the first time for their annual reporting period commencing January 1, 2026. - Amendments to Korean IFRS 1109 Financial Instruments and Korean IFRS 1107 Financial Instruments: Disclosures Korean IFRS 1109 Financial Instruments and Korean IFRS 1107 Financial Instruments: Disclosures have been amended to respond to recent questions arising in practice, and to include new requirements.  clarify the date of recognition and derecognition of some financial assets and liabilities, with a new exception for some financial liabilities settled through an electronic cash transfer system;  clarify and add further guidance for assessing whether a financial asset meets the solely payments of principal and interest (SPPI) criterion;  add new disclosures of impact on the entity and the extent to which the entity is exposed for each type of financial instruments if the timing or amount of contractual cash flow changes due to amendment of contract term; and  update the disclosures for equity instruments designated at fair value through other comprehensive income (FVOCI). - Annual Improvements to Korean IFRS -Volume 11 Annual Improvements to Korean IFRS -Volume 11 should be applied for annual periods beginning on or after January 1, 2026.  Korean IFRS 1101 First-time Adoption of International Financial Reporting Standards: Hedge accounting by a first-time adopter  Korean IFRS 1107 Financial Instruments: Disclosures: Gain or loss on derecognition and implementation guidance  Korean IFRS 1109 Financial Instruments: Derecognition of lease liabilities and definition of transaction price  Korean IFRS 1110 Consolidated Financial Statements: Determination of a 'de facto agent'  Korean IFRS 1007 Statement of Cash Flows: Cost method

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 19 Amendments to Korean IFRS 1109 Financial Instruments and Korean IFRS 1107 Financial Instruments: Disclosures - Contracts Referencing Nature-dependent Electricity Contracts referencing nature-dependent electricity are defined contracts that expose an entity to variability in the underlying amount of electricity because the source of electricity generation depends on uncontrollable natural conditions (for example, the weather). The amendments clarify that 'contracts to buy or sell such electricity' are assessed for eligibility under the own-use exemption. In addition, the amendments modify hedge accounting requirements by allowing an entity to designate as the hedged item a variable nominal amount of forecast electricity transactions that reflect the nature-dependent variability of electricity and introduce additional disclosure requirements. (2) New and amended standards not yet adopted by the Group The following new and amended accounting standards and interpretations have been issued but are not mandatory for the annual reporting period ending on December 31, 2026.: - Korean IFRS 1118 Presentation and Disclosure in Financial Statements Korean IFRS 1118 Presentation and Disclosure in Financial Statements replaces Korean IFRS 1001 Presentation of Financial Statements. Korean IFRS 1118 is expected to increase comparability of the financial performance of similar entities by providing users with more useful information for analyzing and comparing the entity's performance based on the income statement. Korean IFRS 1118 should be first applied for annual periods beginning on or after January 1, 2027, and earlier application is permitted. In accordance with Korean IFRS 1008 Accounting Policies, Changes in Accounting Estimates and Errors, the comparative information for the year ended December 31, 2026, shall be restated under Korean IFRS 1118 as the Group is required to apply the standard retrospectively. When the Group prepares its financial statements by applying Korean IFRS 1118, the following material accounting policies are expected to result in significant differences compared to the current financial statements. These items do not include all differences that may arise in the future and may be subject to change based on the results of additional analysis. • Changes in presentation of income statement • Introduction of disclosure of management-defined performance measures • Changes in classification of cash flows The Group is reviewing the impact of the above-listed amendments on the financial statements.

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 20 2.3 Accounting Policies The material accounting policies and methods of computation used in the preparation of the consolidated interim financial statements are consistent with those of the consolidated financial statements for the year ended December 31, 2025, except for the changes resulting from the application of amendments and enactments of standards described in Note 2.2 (1) and as detailed below. 2.3.1 Income Tax Expense Income tax expense for the interim period is recognized based on management's best estimate of the weighted average annual income tax rate expected for the full financial year. The estimated average annual effective income tax rate is applied to the pre-tax income of the interim period. The Group is subject to Pillar Two income taxes and has reviewed the impact on the financial statements. As aresult of this assessment, no Pillar Two current tax expense is recognized for the current period, and the exception to the recognition and disclosure of deferred taxes has been applied. 3. Critical Accounting Estimates and Assumptions The preparation of financial statements requires the Group to make estimates and assumptions about the future. Management also needs to exercise judgment in applying the Group's accounting policies. Estimates and assumptions are evaluated continuously and are based on historical experience and other factors, including reasonable expectations of future events under the given circumstances. As the resulting accounting estimates will, by definition, rarely equal the actual results, they involve a significant risk of resulting in material adjustments.

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 21 4. Financial Instruments by Category Financial instruments by category as at June 30, 2026 and December 31, 2025, are as follows: (In millions of Korean won) June 30, 2026 Financial assets Financial assets at amortized cost Financial assets at FVTPL Financial assets at FVOCI Derivatives used for hedging Total Cash and cash equivalents ₩ 3,049,813 - - - 3,049,813 Trade and other receivables 8,420,864 - 100,985 - 8,521,849 Other financial assets 1,662,713 996,507 3,207,742 531,038 6,398,000 (In millions of Korean won) June 30, 2026 Financial liabilities Financial liabilities at amortized cost Financial liabilities at FVTPL Derivatives used for hedging Others Total Trade and other payables1 ₩ 6,890,145 - - - 6,890,145 Borrowings 11,270,823 - - - 11,270,823 Other financial liabilities 1,026,315 - 1,981 - 1,028,296 Lease liabilities - - - 1,344,358 1,344,358 1 Amounts related to employee benefit plans are excluded in Trade and other payables (In millions of Korean won) December 31, 2025 Financial assets Financial assets at amortized cost Financial assets at FVTPL Financial assets at FVOCI Derivatives used for hedging Total Cash and cash equivalents ₩ 3,506,971 - - - 3,506,971 Trade and other receivables 7,806,644 - 107,644 - 7,914,288 Other financial assets 1,476,527 774,557 2,423,277 315,537 4,989,898 (In millions of Korean won) December 31, 2025 Financial liabilities Financial liabilities at amortized cost Financial liabilities at FVTPL Derivatives used for hedging Others Total Trade and other payables1 ₩ 6,693,177 - - - 6,693,177 Borrowings 10,785,572 - - - 10,785,572 Other financial liabilities 999,020 105,810 13,862 - 1,118,692 Lease liabilities - - - 1,423,206 1,423,206 1 Amounts related to employee benefit plans are excluded in Trade and other payables

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 22 5. Trade and Other Receivables (1) Trade and other receivables as at June 30, 2026 and December 31, 2025, are as follows: (In millions of Korean won) June 30, 2026 Total amounts Provision for impairment Present value discount Carrying amount Current assets Trade receivables ₩ 3,417,050 (396,556) (8,232) 3,012,262 Other receivables 3,447,988 (104,869) (1,577) 3,341,542 Total ₩ 6,865,038 (501,425) (9,809) 6,353,804 Non-current assets Trade receivables ₩ 326,548 (1,261) (17,651) 307,636 Other receivables 1,950,825 (81,087) (9,329) 1,860,409 Total ₩ 2,277,373 (82,348) (26,980) 2,168,045 (In millions of Korean won) December 31, 2025 Total amounts Provision for impairment Present value discount Carrying amount Current assets Trade receivables ₩ 3,331,715 (385,739) (7,959) 2,938,017 Other receivables 3,014,911 (104,747) (3,032) 2,907,132 Total ₩ 6,346,626 (490,486) (10,991) 5,845,149 Non-current assets Trade receivables ₩ 330,619 (1,290) (15,703) 313,626 Other receivables 1,850,564 (86,270) (8,781) 1,755,513 Total ₩ 2,181,183 (87,560) (24,484) 2,069,139

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 23 (2) Details of other receivables as at June 30, 2026 and December 31, 2025, are as follows: 1 As at June 30, 2026, credit sales asset of ₩ 1,767,211 million (December 31, 2025: ₩ 1,550,049 million) held by BC Card Co., Ltd. are included. (3) The maximum exposure of trade and other receivables to credit risk is the carrying amount of each class of receivables mentioned above as at June 30, 2026. (4) The Group classifies a certain portion of trade receivables as financial assets at fair value through other comprehensive income, based on business model for managing the asset and the cash flow characteristics of the contract. (In millions of Korean won) June 30, 2026 December 31, 2025 Loans ₩ 49,244 61,915 Receivables 1 2,791,282 2,458,065 Accrued income 51,644 47,802 Refundable deposits 239,872 241,287 Loans receivable 1,965,197 1,753,505 Finance lease receivables 245,282 245,055 Others 45,386 46,033 Less: Provision for impairment (185,956) (191,017) Total ₩ 5,201,951 4,662,645

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 24 6. Other Financial Assets and Liabilities (1) Details of other financial assets and liabilities as at June 30, 2026 and December 31, 2025, are as follows: (In millions of Korean won) June 30, 2026 December 31, 2025 Other financial assets Financial assets at amortized cost 1 ₩ 1,662,713 1,476,527 Financial assets at fair value through profit or loss 1,2 996,507 774,557 Financial assets at fair value through other comprehensive income 3,207,742 2,423,277 Derivatives used for hedging 531,038 315,537 Less: Non-current (4,227,939) (3,362,916) Current ₩ 2,170,061 1,626,982 Other financial liabilities Financial liabilities at amortized cost 3,4 ₩ 1,026,315 999,020 Financial liabilities at FVTPL - 105,810 Derivatives used for hedging 1,981 13,862 Less: Non-current (585,479) (592,599) Current ₩ 442,817 526,093 1 As at June 30, 2026, the Group's financial instruments amount to ₩ 121,315 million (December 31, 2025: ₩ 118,946 million) and consist of checking account deposits, time deposits, and others which are subject to withdrawal restrictions. 2 As at June 30, 2026, the Group provided investments in Korea Software Financial Cooperative and others amounting to ₩ 11,025 million (December 31, 2025: ₩ 10,695 million) as a collateral in exchange for the payment guarantee provided by the Korea Software Financial Cooperative and others. 3 The amount includes liabilities related to the obligation to acquire additional shares in Epsilon Global Communications Pte. Ltd. and kt Cloud Co., Ltd. (Note 16). 4 The amount includes liabilities convertible preferred stock issued by kt Cloud Co., Ltd. (Note 16).

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 25 (2) Financial Assets at fair value through profit or loss 1) Details of financial assets at fair value through profit or loss as at June 30, 2026 and December 31, 2025, are as follows: (In millions of Korean won) June 30, 2026 December 31, 2025 Equity instruments (Listed) ₩ - 3,562 Equity instruments (Unlisted) 46,342 46,955 Debt instruments 948,326 723,978 Derivatives held for trading 1,839 62 Total 996,507 774,557 Less: Non-current (733,776) (709,412) Current ₩ 262,731 65,145 2) The maximum exposure to credit risks for debt instruments of financial assets at fair value through profit or loss is the carrying amount of each class of debt instruments above as at June 30, 2026. (3) Financial Assets at fair value through other comprehensive income 1) Details of financial assets at fair value through other comprehensive income as at June 30, 2026 and December 31, 2025, are as follows: (In millions of Korean won) June 30, 2026 December 31, 2025 Equity instruments (Listed) ₩ 2,838,278 2,044,789 Equity instruments (Unlisted) 364,139 372,341 Debt instruments 5,325 6,147 Total 3,207,742 2,423,277 Less: Non-current (3,207,742) (2,423,277) Current ₩ - - 2) Upon disposal of these equity investments, any balance within the accumulated other comprehensive income is reclassified not to profit or loss, but to retained earnings. Upon disposal of these debt investments, the remaining balance of the accumulated other comprehensive income is reclassified to profit or loss.

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 26 (4) Derivatives used for Hedging 1) Details of valuation of derivatives used for hedging as at June 30, 2026 and December 31, 2025, are as follows: (In millions of Korean won) June 30, 2026 December 31, 2025 Assets Liabilities Assets Liabilities Interest rate swap ₩ 3,032 - 1,810 - Currency swap 1 528,006 1,981 313,727 13,862 Total 531,038 1,981 315,537 13,862 Less: Non-current (254,390) (240) (202,144) (13,862) Current ₩ 276,648 1,741 113,393 - 1 The expected maximum period during which the Group is exposed to cash flow variability arising from the forecast transactions designated as hedged items is until September 7, 2034. The entire fair value of a hedging derivative is classified as a non-current asset or liability if the remaining maturity of the hedged item exceeds 12 months and, as a current asset or liability, if the maturity of the hedged item is within 12 months. 2) Details of valuation gains and losses on the derivative instruments for the six-month periods ended June 30, 2026 and 2025, are as follows: (In millions of Korean won) 2026 2025 Type of transaction Valuation gain Valuation loss Other comprehensive Income(loss)1 Valuation gain Valuation loss Other comprehensive Income(loss)1 Interest rate swap ₩ 24 - 1,346 2 103 (82) Currency swap 220,062 1,149 7,111 2,408 252,754 22,239 Total ₩ 220,086 1,149 8,457 2,410 252,857 22,157 1 The amounts are before adjustments for deferred income tax and allocations to non-controlling interests and have been directly reflected in equity. 3) The effective portion recognized in other comprehensive income related to cash flow hedges amounts to valuation gains of ₩ 227,543 million for the six-month period ended June 30, 2026 (for the six-month period ended June 30, 2025: valuation loss of ₩ 229,194 million). The ineffective portion recognized in profit or loss related to cash flow hedges amounts to valuation gains of ₩ 706 million as current profit or loss for the six-month period ended June 30, 2026 (for the six-month period ended June 30, 2025: ₩ 434 million). In addition, the valuation gains reclassified from other comprehensive income to profit or loss amounts to ₩ 219,086 million for the six-month period ended June 30, 2026 (for the six-month period ended June 30, 2025: valuation loss of ₩ 251,351 million).

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 27 (5) Financial Liabilities at fair value through profit or loss 1) Details of financial liabilities at fair value through profit or loss as at June 30, 2026 and December 31, 2025, are as follows: (In millions of Korean won) June 30, 2026 December 31, 2025 Derivatives held for trading 1 ₩ - 105,810 1 This represents derivative liabilities recognized in relation to the shareholders' agreement entered into with financial investors participating in the paid-in capital increase of K Bank Inc., which were extinguished during the current period upon the listing of K Bank Inc. 2) The valuation gain and loss on financial liabilities at fair value through profit or loss for the six-month periods ended June 30, 2026 and 2025, are as follows: (In millions of Korean won) 2026 2025 Valuation gain Valuation loss Valuation gain Valuation loss Derivatives liabilities held for trading ₩ - 4,582 17,254 3,447 7. Inventories Inventories as at June 30, 2026 and December 31, 2025, are as follows: (In millions of Korean won) June 30, 2026 December 31, 2025 Acquisition cost Valuation allowance Carrying amount Acquisition cost Valuation allowance Carrying amount Merchandise ₩ 621,424 (22,769) 598,655 421,615 (31,188) 390,427 Others 27,058 (55) 27,003 25,763 (55) 25,708 Total ₩ 648,482 (22,824) 625,658 447,378 (31,243) 416,135 Cost of inventories recognized as expenses for the six-month period ended June 30, 2026 amounts to ₩ 1,746,290 million (for the six-month period ended June 30, 2025: ₩ 2,120,945 million) and reversal valuation loss on inventory amounts to ₩ 8,419 million for the six-month period ended June 30, 2026 (for the six-month period ended June 30, 2025: ₩ 57,294 million).

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 28 8. Other Assets and Liabilities Other assets and liabilities as at June 30, 2026 and December 31, 2025, are as follows: (In millions of Korean won) June 30, 2026 December 31, 2025 Other assets Advance payments ₩ 237,524 177,929 Prepaid expenses 356,223 262,230 Contract cost 2,082,992 2,099,088 Contract assets 1,035,148 1,026,260 Others 13,935 20,431 Less: Non-current (1,107,635) (1,017,830) Current ₩ 2,618,187 2,568,108 Other liabilities Advances received 1 ₩ 406,498 390,216 Withholdings 128,145 140,817 Unearned revenue 1 51,311 42,197 Lease liabilities 1,344,358 1,423,206 Contract liabilities 212,051 239,738 Others 26,214 57,793 Less: Non-current (1,035,627) (1,108,141) Current ₩ 1,132,950 1,185,826 1 The amounts include adjustments arising from adoption of Korean IFRS 1115 Revenue from Contracts with Customers (Note 20). 9. Assets Held-for-sale For the period ended June 30, 2026, the Group classified ₩ 2,426 million of certain tangible and intangible assets and other assets as non-current assets held for sale, as it had decided to dispose them. The asset was measured at net fair value in accordance with K-IFRS 1105. The details of the assets held for sale are as follows: (in millions of Korean won) June 30, 2026 December 31, 2025 Machinery and equipment ₩ - 1,890 Other Intangible assets 926 926 Others 1,500 1,500 Total ₩ 2,426 4,316

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 29 10. Property and Equipment, Investment Properties, and Intangible Assets (1) Changes in property and equipment for six-month period ended June 30, 2026 and 2025, are as follows: (In millions of Korean won) 2026 2025 Beginning, net ₩ 14,258,472 14,825,814 Acquisition and capital expenditure 908,654 1,014,710 Disposal and termination (52,297) (46,182) Depreciation (1,362,240) (1,415,575) Transfer to investment properties (34,165) (11,028) Changes in consolidation scope - (3,644) Impairment Loss (81) - Others 1 (22,417) (137,726) Ending, net ₩ 13,695,926 14,226,369 1 Amounts include transfers to intangible assets. (2) Changes in investment properties for the six-month period ended June 30, 2026 and 2025, are as follows: (In millions of Korean won) 2026 2025 Beginning, net ₩ 2,872,049 2,299,616 Acquisition and capital expenditure 134,606 643,954 Disposal (1,469) - Depreciation (34,421) (41,231) Transfer from property, plant and equipment 34,165 11,028 Changes in consolidation - (3,401) Others (5,083) 7,623 Ending, net ₩ 2,999,847 2,917,589 (3) As at June 30, 2026, the Group (Lessor) has entered into a non-cancellable operating lease contract for real estate. The future minimum lease payments under this contract amount to ₩ 189,683 million for one year or less, ₩ 388,444 million for more than one year and less than five years, ₩ 188,047 million for over five years, and ₩ 766,174 million in total.

KT Corporation and Subsidiaries Notes to the Condensed Consolidated Interim Financial Statements As at June 30, 2026 and 2025 (Unaudited) , and December 31, 2025 30 (4) Changes in intangible assets for the six-month period ended June 30, 2026 and 2025, are as follows: (In millions of Korean won) 2026 2025 Beginning, net ₩ 1,556,621 1,862,740 Acquisition and capital expenditure 1 635,510 191,444 Disposal and termination (1,165) (6,792) Amortization (294,791) (303,639) Impairment (199) (821) Changes in consolidation scope - (34,653) Others (21,995) (9,753) Ending, net ₩ 1,873,981 1,698,526 1 Amounts include transfers from property and equipment. (5) The carrying amount of membership rights with an indefinite useful life not subject to amortization, except for goodwill, is ₩ 208,781 million as at June 30, 2026 (December 31, 2025: ₩ 201,308 million). (6) Goodwill is allocated to the Group's cash-generating units, which are identified by operating segments. As at June 30, 2026, the goodwill allocated to each cash-generation unit is as follows: (In millions of Korean won) Cash-Generating Unit Amount Mobile services ₩ 65,057 BC Card Co., Ltd.. 41,234 kt Mill