1840
The Post Office was established in order to meet postal requirements, and started to provide telecommunication services in the following years.
1909
With the addition of telephone services, the institution was transformed into the PTT Directorate.
1994
Türk Telekomünikasyon A.Ş. was established on 30th June.
1995
On 24th April, the telecommunications and postal services in the PTT were separated. All of the PTT's staff, assets and liabilities related to telecommunications services were transferred to Türk Telekom, which was fully owned by the Republic of Turkey Prime Ministery Undersecretariat of Treasury.
2004
Through the merger between Türk Telekom's GSM Operator, Aycell, and İş-TİM on 19th February, TT & TİM İletişim Hizmetleri A.Ş. was established.
The trade name of TT & TİM İletişim Hizmetleri A.Ş. was changed to Avea İletişim Hizmetleri A.Ş. (Avea) on 15th October.
2005
Work on the privatization of Türk Telekom was completed on 14th November, and 55% of its shares were transferred to Oger Telekomünikasyon A.Ş.
2006
TTNET, a subsidiary of Türk Telekom, was established and started operations on 14 May after obtaining the internet service provider license.
On 15th September, Türk Telekom purchased a 40.56% stake in İş-TİM for USD 500 million and increased its share in Avea to 81.12%.
2008
A 15% stake in Türk Telekom was offered to the public on 15 May and began trading on the Istanbul Stock Exchange; at the time, it was the most successful public offering to have taken place in Turkey over the last 4 years.
2010
Türk Telekom acquired Invitel International (which became Türk Telekom International), the leading wholesale capacity provider in Central and Eastern Europe.
2011
Türk Telekom became the first telecommunication company in Turkey to report carbon emissions to the CDP (Carbon Disclosure Project).
2012
Türk Telekom's total share in Avea's capital increased to 89.99%.
2013
Sobee Yazılım Ticaret Ltd. Şti., a wholly-owned subsidiary of Türk Telekom, was transferred to TTNET A.Ş., also a subsidiary of Türk Telekom, with all of its assets and liabilities, through a merger.
Under a resolution taken by the Board of Directors, Türk Telekom restructured its senior management, including the merger of the Group CEO and General Manager positions.
2014
Türk Telekom conducted bond issuances with a maturity of 5 and 10 years, totalling USD 1 billion. The issuance received considerable attention from international investors and was eight times oversubscribed. The transaction, which at that time was largest corporate bond issuance in Turkey, was the first to be issued with two different maturities simultaneously.
The international rating agency, Fitch Ratings, assigned a BBB-“(investment grade) rating to Türk Telekom's TL and foreign currency long-term credit rating with a “Stable" outlook.
International credit rating agency Standard & Poor (S&P) upgraded Türk Telekom's credit rating from “BB +" to “BBB-“ (investment grade), emphasizing that Türk Telekom had strengthened its liquidity position with its successful bond issuance of USD 1 billion in June 2014.
TTNET A.Ş. purchased the rights to broadcast the UEFA Champions League and UEFA European League in Turkey for three seasons, starting with the 2015-2016 season. The games were broadcast over the Türk Telekom Group's broadcasting platform, Tivibu.
2015
Türk Telekom became the sole owner of Avea İletişim Hizmetleri A.Ş. with the completion of the transfer of the shares of Avea owned by the İş Bank Group, to Türk Telekom.
Türk Telekom International became a full member of the SEA-ME-WE-5 underwater cable consortium that would connect 17 countries.
Avea participated in the Authorization Tender for IMT Services and Infrastructure (known as the LTE Authorization Tender) that was carried out on 26 August by the Information and Communication Technologies Authority (ICTA). Expanding its capacity with the packages that it had purchased in different frequency bands, Avea became the operator offering the widest frequency per subscriber.
2016
Avea, Türk Telekom and TTNET brands were unified under the “Türk Telekom" single brand in order to offer mobile, internet, telephony and TV services from a single channel.
Türk Telekom became the first operator to integrate ULAK into its network. ULAK was developed by Aselsan, Netaş and Türk Telekom's R&D subsidiary, Argela with the support of the Undersecretariat of Defence Industry, and is Turkey's first domestic and national LTE base station.
Türk Telekom introduced its new youth brand, Selfy, to young people.
With the decision taken by the Board of Directors of Türk Telekom, Paul Doany, who is widely renowned throughout the sector, was appointed as the CEO-General Manager of the company on 26th September.
Türk Telekom became the first operator to test the Narrowband IoT (Narrowband Internet of Things) technology on its own network in Turkey in cooperation with Nokia.
The SEA-ME-WE-5 underwater cable system, which Türk Telekom International is a participant, started service at the end of the year, connecting 17 countries from Asia to Europe over a total distance of more than 20,000 kilometers.
2017
TT Ödeme Hizmetleri A.Ş. a subsidiary of Türk Telekom obtained a payment services license from the Banking Regulation and Supervision Agency (BRSA) in order to provide new generation payment services to its customers.
A total of 6.68% of the Türk Telekomünikasyon A.Ş. shares that belonged to the Undersecretariat for Treasury of the Prime Ministry of the Republic of Turkey (5% Group B, 1.68% Group D) were transferred to the Turkey Wealth Fund following the related Council of Ministers' decision.
The 5G Center of Excellence, which was designed for the development of national 5G technologies, was opened in Ankara by Argela, the R&D subsidiary of Türk Telekom.
Türk Telekom renewed and promoted the “Türk Telekom Prime" brand, which offers exclusive services to its customers.
Turkey's two well-established, institutions Türk Telekom and PTT A.Ş., extended the Pttcell cooperation initiated in 2013 in the mobile communications field for a further 5 years.
Türk Telekom was selected as the most valuable brand in Turkey in the “Turkey's 100 Most Valuable Brands" list, which is prepared annually by the international brand valuation company, Brand Finance.
Established by Türk Telekom and Vodafone, the Avea-Vodafone Evrensel İş Ortaklığı won the tender organized by the Ministry of Transport, Maritime Affairs and Communications in order to provide services under the Universal Service Fund to 1,472 residential areas with no mobile communication infrastructure.
Türk Telekom maintained its top ranking in terms of the sales revenues among the 500 IT companies, according to a survey conducted by Bilişim 500, Turkey's leading IT sector organization, for the 18th year.
Türk Telekom introduced TAMBU, a platform-enabled digital keyboard that it developed with the vision of developing domestic and national technology.
Türk Telekom introduced its digital music platform Muud, which it renewed with improvements to its technological infrastructure.
Türk Telekom rose to second ranking in the Pay-TV market thanks to its superior technology and rich content.
Türk Telekom became the first Turkish company to join in the ONF (Open Networking Foundation) platform with a member status and to enter the management. ONF, which includes global technology giants as members, designs 5G and beyond technologies.
Türk Telekom became a platinum member of the Open Network Automation Platform (ONAP), which brings together leading global operators and technology suppliers.
Netsia, the US subsidiary of Türk Telekom's R&D company Argela, successfully established “RAN Slicing" technology in Orange, Verizon and Telefonica.
2018
Türk Telekom's new head office building, which is home to Türk Telekom's critical management centers such as Turkey's largest Cyber Security Center and Network Management Center (NMC), the Center of Excellence and the Crisis Center was opened in Ankara.
Argela obtained a total of 17 patents in the 5G field from the US Patent and Trademark Office through its subsidiary, Netsia.
In line with its focus on investing in early-stage and scalable companies, Türk Telekom established TT Ventures, the first corporate venture capital company in the Turkish telecommunications sector. The company undertook its first investment in Doctor Turkey, one of the first ventures in the field of online health services in Turkey.
In order to increase internet penetration and diversify sales channels, collaborations were made with electricity companies in what was a first in Turkey. Türk Telekom fixed broadband packages and electricity started to be offered from a single point.
Türk Telekom was selected as “Turkey's most valuable telecommunications brand" for the tenth time in a row in the “Telecoms 500", a ranking published annually by the international brand valuation company, Brand Finance.
The trademark of Türk Telekom's mobile communication company, Avea, was changed to TT Mobil İletisim in order to be consistent with the company's single brand perception.
A cooperation protocol was signed between Türk Telekom, Turkcell, Vodafone, Türksat and Telkoder for “Leasing of Fixed Electronic Communication Infrastructure". The protocol is aimed at ensuring the effective use of fixed infrastructure, minimizing duplicate investments, accelerating new investments, offering a high-level customer experience and managing environmental issues more effectively.
In order to expand the mobile infrastructure, first pilot project for active mobile network sharing, which includes network expansion and site consolidation in Zonguldak, were completed successfully.
With the goal of becoming the data hub in Turkey and the region, Türk Telekom opened its largest data center in Esenyurt, Istanbul. The number of Türk Telekom data centers increased to seven.
The Turkey Football Federation started to use the Video Assistant Referee (VAR) system in the Super League thanks to the MTN (Media Transport Network) infrastructure - a new technology which Türk Telekom was the first operator to utilize.
Türk Telekom purchased the broadcasting rights of the Turkey Basketball Super League and All Star games, which are among Europe's most valuable three leagues, and the Women's Basketball Super League, the Women's and Men's Turkish Cup games for three seasons starting from the 2018-2019 season. The games will be broadcast exclusively from Tivibu for three seasons.
Türk Telekom's live mobile knowledge quiz program, “Eleq", offering monetary prizes started broadcasting.
On 21 December 2018, 55% of the shares held by Ojer Telekomünikasyon A.Ş. (“OTAŞ") in Türk Telekomünikasyon A.Ş. were transferred to Levent Yapılandırma Yönetimi A.Ş. (LYY), which is a special purpose vehicle, whose shareholders are the creditor banks that provided loans to OTAŞ.