So I travel here and there and usually have no problems with my phone wherever I go, with the the exception of Turkey, Turkey has always given me problems. Whenever I go there I essentially have to buy a disposable mobile. This is because they block your phone with the IMEI number from their networks. To avoid hassle and/or cost I decided I would buy a cheap Turkish mobile phone there for use there exclusively. After a while of travelling there and back (and very limited use) its microphone became very weak to the point where I have to shout for the person on the other side to hear me. So I bought another different mobile, again same problem developed after a while. At this point I'm thinking that it would have been easier just to look in to somehow registering my own phone. Has anybody registered a mobile phone in Turkey? Is the process straightforward? Is there any downside to doing so?

? Why not ATT international, I never had problems in Turkey with iphone4, roaming via ATT international.

You obviously had a short holiday then.
After I think 2 weeks or so it gets blocked, and remains on the "blacklist" for around a year.

And imagine roaming costs!

Fom what I know, turkey is very restrictive regarding 'unknown' phones (IMEIs) in their networks.
I believe the only way is to buy one again. Or get a contract over there (maybe it is possible to register than your own IMEI).
But I do not know more, sorry.

Or change the IMEI - IIRC this is (was?) a common Asian back-street business couple of years ago.

Is that illegal? if so I'd like to avoid it because I don't want to come back only to realise I've created more trouble than I've solved.

Hahaha , welcome to Turkey We have 3 networks here.Turkcell , Avea and Vodafone.Turkcell is best.If you want to get clear sounds with your phone you should use Turkcell.

Use your own network with active roaming state.

If you're talking about registering your own phone for use in country , you can do this in customhouse or airports.But you need to have Turkish Passport and 100 Lira Don't event try to change your IMEI.And also we have Wireless Phone Tax (1.1 Lira or 0.6$ per month)

You can register your phone, but you have to pay 100TL (Turkish Lira). This rule has just begun like a month ago. before, it was only like 10TL.

People brought many (illegal) phones from outside turkey, so they've made the registering much expensiver...

Glad i've registered mine JUST BEFORE the rule went alive

By the way, you only have to register if you want to use a Turkish local simcard. (Turkcell, Vodafone, Avea. I prefer Vodafone!)

Good to know. Another reason on my "Why i do not want to go to Turkey, unless $company beats me into submission" list.

You can just use your own simcard without any problems