Why is my Lumia 520 not getting updated to Lumia Denim?

[Windows Central Question]

I got my phone from my brother living in US. I live in India. This is an AT&T Lumia 520. I'm still stuck on Lumia Cyan. My all other friends having Lumia 520 have got their denim updates. Whenever I check for updates, it shows that my phone is up to date. Is it some issue with AT&T? or is it a region issue?

 

[xandros9]

It's because ATT and other US carriers tend to range from mediocre to horrible in terms of pushing updates. (with some odd exceptions like Lumia Black on the 1020, Denim + Update 2 on the postpaid 635...)

I wouldn't be surprised if our ATT 820, 920, and 520's have seen their last update already.

However, for older phones like those, Lumia Denim isn't much of a change, and if you use the Preview for Developers program, you can get onboard 8.1 Update 1 which has pretty much all you need with minimal fuss.