Hello, @smailuk. Thanks for reaching out to us about unlocking your device.

When submitting the unlock request, at the top of the page, it should say "Do you have an AT&T Number?" and then it will give you the option to say "Yes" or "No". Make sure you select "No" and then continue submitting your request.

Also, here is more info about unlocking your device.

Let us know if this works!

TT, AT&T Community Specialist

If you don't get a satisfactory response and assistance through ATT help and this forum you can file an FCC complaint online. FCC complaint is a simple free form and the complaint is forwarded back to AT&T upper management.

There are at least a dozen complaints a day about AT&T's broken unlock portal that's been going on for over a month. AT&T has still not fixed its whacked system

@ATTHelp  , "Do you have an AT&T Number?" and then it will give you the option to say "Yes" or "No". Make sure you select "No" and then continue submitting your request."  --- that's exactly what I did, I have select "No".

And after couple minutes received  email from AT&T  saying "Heads up! We can't complete your unlock request right now" (((

I have tried 2 times, but with same result ( 

@formerlyknownas  , appreciate Your advise, I've also read  topics with same problem  here , so will Google for FCC Complaining as an optional way.

Thank you for reaching back out ot us with that information, @smailuk. At this time, we would like to speak with you in private, so we can investigate why you are receiving this error message while trying to unlock your device. Please click the message icon in the upper right and reply.

We look forward to speaking with you!

TT, AT&T Community Specialist

Thank You 2 everyone here, problem was solved in couple minutes by @ATTHelp  in PM!!! 
Thank You for super fast support !
Did not expect to be so easy !!!!