[6-K] TURKCELL ILETISIM HIZMETLERI A S Current Report (Foreign Issuer)

Rhea-AI Filing Summary

Turkcell Iletisim Hizmetleri A.S. reported that the capital of its wholly owned subsidiary Kıbrıs Mobile Telekomünikasyon Limited has been increased by TRY 500,000,000 to a total of TRY 922,724,863.

Turkcell’s pre-emption rights in this capital increase were fully paid, meaning the company participated in the increase and maintained its ownership in Kıbrıs Telekom.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER

PURSUANT TO RULE 13a-16 OR 15d-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of November 2025

Commission File Number: 001-15092

TURKCELL ILETISIM HIZMETLERI A.S.

(Translation of registrant’s name into English)

Aydınevler Mahallesi İnönü Caddesi No:20

Küçükyalı Ofispark

34854 Maltepe
Istanbul, Türkiye

(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:

x Form 20-F  ¨ Form 40-F

Enclosure: A press release dated November 17, 2025, announcing the capital increase of the registrant's subsidiary, Kıbrıs Telekom.

Istanbul, November 17, 2025

Announcement Regarding Kıbrıs Telekom Capital Increase

The capital of our Company's wholly-owned subsidiary, Kıbrıs Mobile Telekomünikasyon Limited ("Kıbrıs Telekom"), has been increased by TRY 500,000,000 to TRY 922,724,863. Our Company's pre-emption rights with respect to the capital increase is fully paid.

For more information:

Turkcell Investor Relations

investor.relations@turkcell.com.tr

Tel: + 90 212 313 1888

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, Turkcell Iletisim Hizmetleri A.S. has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	TURKCELL ILETISIM HIZMETLERI A.S.
Date: November 17, 2025	By:	/s/ Özlem Yardım
		Name:	Özlem Yardım
		Title:	Investor Relations Corporate Finance Director

	TURKCELL ILETISIM HIZMETLERI A.S.
Date: November 17, 2025	By:	/s/ Kamil Kalyon
		Name:	Kamil Kalyon
		Title:	Chief Financial Officer

FAQ

What did Turkcell (TKC) announce regarding Kıbrıs Telekom?

Turkcell announced that the capital of its wholly owned subsidiary Kıbrıs Mobile Telekomünikasyon Limited has been increased, and Turkcell fully paid its pre-emption rights.

By how much was Kıbrıs Telekom’s capital increased?

Kıbrıs Telekom’s capital was increased by TRY 500,000,000, bringing its total capital to TRY 922,724,863.

Does Turkcell still fully own Kıbrıs Telekom after the capital increase?

Yes. The announcement states that Kıbrıs Telekom is a wholly owned subsidiary of Turkcell and that Turkcell’s pre-emption rights in the capital increase were fully paid.

What are pre-emption rights in the context of Turkcell’s capital increase?

Pre-emption rights give an existing shareholder, like Turkcell, the opportunity to buy new shares in a capital increase so that its ownership stake is maintained. Turkcell’s pre-emption rights were fully paid.

Which subsidiary of Turkcell is affected by this capital increase?

The capital increase relates to Turkcell’s wholly owned subsidiary Kıbrıs Mobile Telekomünikasyon Limited, also referred to as Kıbrıs Telekom.

In what currency was the Kıbrıs Telekom capital increase announced?

The capital increase for Kıbrıs Telekom was announced in Turkish Lira (TRY), with an increase of TRY 500,000,000 to a total of TRY 922,724,863.