Turkcell Iletisim Hizmetleri A S

UNDER THE SECURITIES EXCHANGE ACT OF 1934

TURKCELL İLETİŞİM HİZMETLERİ A.Ş.

(Translation of registrant's name into English)

Turkcell Küçükyalı Plaza

Aydınevler Mahallesi, İsmet İnönü Caddesi, No:20

Küçükyalı B Blok Ofispark

(Address of Principal Executive Offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Enclosure: A press release dated October 23, 2026 announcing the registrant's share buy-back transactions.

Announcement Regarding the Share Buy-back Transactions

Within the scope of our Company's buy-back program, with the aim of protecting the interests of our stakeholders and supporting healthy price formation in the market while maintaining the fair value of our shares, on October 23, 2026, a total of 3,201,696 shares were purchased at an average price level of TRY 86.75. The total transaction value is TRY 277,731,356.

The details of the buy-back transactions Code of Share Subject to

Buy-back Transaction Date Nominal Value of