Q: how can i update my apple id on my phone

Hello alastairfrompretoria,

I understand you have an Apple ID from an old email address that is no longer used so you want to change it.

First make sure you do actually change the Apple ID to the new email address rather than creating a new Apple ID. (Note the first step is to sign out of everything with the old version first.)

Change your Apple ID - Apple Support

Then sign into everything again with the newly renamed Apple ID.

Sign in with a different Apple ID on your iPhone, iPad, or iPod touch - Apple Support

You may want to read through them both before making the change to get the full picture.

Take care.