How can I update my phone?

[AC Question]

I just recently purchased an HTC One M7 (AT&T) from Amazon. I know that it was updated to Lollipop, (my dad has the same phone) but when I check for updates, it gives a popup saying that I'm up to date. I'm currently on 4.4.2. That's not Lollipop. Any help would be appreciated!

 

[B. Diddy]

Welcome to Android Central! Are you currently on AT&T? Since the carrier often pushes the update for carrier-branded phones, you might need to be on the AT&T network to receive the update.

 

[trevynbeck]

No, I am on Cricket's network. Would I need an AT&T sim to get the update?