I've changed my apple ID to a different email address as the current email address is now defunct!
So I've managed to changed via itunes and logged in on my mac and in the settings of my iphone its showing my current email address too!
But as I try and update my apps on my iphone, which goes to the screen with the login details, it's still showing as my old email address! Highly frustrating! I have restored my iphone and backed up too, but the problem still exists!
I'm guessing because I bought all the apps in my old Apple ID, its not wanting too update?
Apps are DRM protected & tied to the account used to originally obtain them. They cannot be transferred to another iTunes account. They can only be updated using the account used to originally obtain them. If that account is no longer valid, you'll have to contact iTunes support and request they add your apps to your new account's download queue: