You have a mobile phone from your country, you came to Turkey, got a Turkish sim card and then after some days you received an SMS from BTK (IT and Communication Authority) and the following days your phone is blocked. You have 120 days to register your phone after your arrival day.
If you do not want to register your phone you can buy a cheap phone from stores.
It is because of your phone is not registered to Mobile Devices Registration System. We are going to explain how to register your phone to this system:
First step: Tax Office
After you arrive to Turkey. Your passport is stamped by police at the customs. After this date you have 120 days to register your mobile phone. If not you may need one new entrance stamp in order to make the registration process.
Take your passport, 1.838 TL with you and go to Beyoglu Vergi Dairesi (Beyoglu Tax Office) it is near Şişhane metro station and Tunnel Square. After you get in the building you should go straight and ask for Vezne (Payment Desk).
They will ask you IMEI number of your mobile. You can learn it by pushing this digits:
After you learn your IMEI number write it down to a paper with your passport name and passport number. You will pay 1.838 TL and you will get a receipt. Here there is something you should pay attention.
Please check the details at your receipt is correct or not. IMEI number, your name, surname and passport number. If there is a mistake you can not register your phone with this receipt. You will pay the tax again with the correct information.
Second Step: Registration
You can register by two options if you have residence permit or not.
Registration without residence permit:
After you received your correct receipt. You can go to your mobile operator company store in Taksim (Türk Telekom, Vodafone or Turkcell) in order to register your phone.
Mobile companies are charging for the registration around 100-150 TL (excluding the sim card fee). So, you will pay in total 1.938-1.988 TL for mobile registration.
Registration with residence permit by e-Devlet:
You can go to any PTT office and get a e-devlet password with your residence permit card. Then you can log in and register your phone to e-devlet website. In order to register your phone to the system you need to pay your tax in advance with the correct details.
Briefly, if you would like to use Turkish Sim card at your mobile phone you should register your phone to BTK system, but if you think that 1.838 TL is too much to pay as a tax, it makes more sense to buy a cheap smart phone or a cell phone already registered to BTK system.