old iTunes accounts coming up after updating devices and cannot change
After updating my iPhone 6 and iPad, iTunes has defaulted back to iTunes accounts that no longer exist. How can I change this?
iPhone 6s, iOS 9.0.1
You can log out of an account by tapping on it in Settings > App And iTunes Stores on your iPad and iPhone, and you can then log in with a different account.
If you have any apps etc on the iPad or iPhone that were downloaded by your old accounts then they will remain tied to the old accounts, so only that account can download future updates to them.