IPad Apple ID

Be aware that switching to using an entirely different AppleID account will cause you to lose access to any paid Apps, Apple services and subscriptions - as these are forever associated with the AppleID account from which they were purchased.

An AppleID account is intended to be used for life. If you need to change the primary email address that identifies your account, or your secondary (recovery) email addresses or trusted telephone numbers, you simply need to update your AppleID account as necessary.

Change your Apple ID - Apple Support

Change your Apple ID password - Apple Support

What to do after you change your Apple ID or password - Apple Support

Change, add, or remove Apple ID payment methods - Apple Support

Few of us will have the luxury of forever keeping the same email addresses or telephone numbers - sometimes these needing to be changed for a variety of reasons. However, updating our AppleID account, maintaining access to our data and purchases, is easy and relatively straightforward - accommodating life’s many changes as they occur.

If you do wish to change and use an entirely different AppleID, first ensure that you have disabled the Activation Lock that will otherwise cause difficulties in the future. You can disable the Activation Lock by disabling the Find My iPad service from iPad settings before trying to use a different AppleID account:

Settings > [Your Name / AppleID] > Find My > Find My iPad - set to OFF

Having disabled the Activation lock, you can now sign-out from your old AppleID:

Settings > [Your Name / AppleID] > Sign Out

Presumably you’ll want to keep any iCloud data that is locally stored on your iPad. If so, accept the opportunity to keep a local copy of your data (e.g., Calendar, Contacts, Notes, Keychain Passwords etc.) - as otherwise this data will be wiped from your iPad as you sign-out from iCloud. After signing out, a restart of your iPad is recommended:

Restart your iPad - Apple Support

After restarting, you can sign-in to your new AppleID account from iPad settings. Any iCloud data that you saved to your iPad during the previous sign-out will be merged with your new AppleID account.