How to Stop macOS from Asking for an Old iCloud Password

Your Mac keeps showing a password prompt for an iCloud address you no longer use, and entering the current password does not make it stop. The prompt is not coming from the Apple Account you are signed in with; it comes from a leftover entry in Internet Accounts, Mail, Messages, or the keychain that still holds the old address. Removing or updating that one entry ends the prompt.

Check which Apple Account is signed in

Open System Settings and click your name at the top of the sidebar. Confirm the email address under your name is the account you use now. If the prompt names a different address, the old account lives somewhere further down the list, not here.

Remove the old account from Internet Accounts

Go to System Settings, Internet Accounts. Look for a second iCloud entry or an account named after the old address. Select it and click the minus button (or Delete Account). If it is an account you still use but changed the password on, select it and enter the new password when prompted instead of deleting it.

Check the account list in Mail

Open Mail, then choose Mail, Settings, Accounts. Old iCloud accounts sometimes survive here after being removed elsewhere. Select the stale one and click the minus button.

Delete the outdated keychain item

Open Keychain Access. Search for it with Spotlight if it is not in Applications, Utilities. Search for the old address. Items named iCloud, or with the old address in the Account column, are what the prompt is trying to refresh. Delete only items you recognize as belonging to the old account and leave anything you are unsure about.

Sign out and back in as a last resort

Go to System Settings, click your name, scroll to the bottom, and click Sign Out. Choose to keep a copy of your data when asked, then sign back in with the account you use now. This rebuilds every iCloud credential on the Mac.

If the prompt only appears in Messages or FaceTime. Those apps hold their own sign-in. Open Messages, Settings, iMessage or FaceTime, Settings, sign out of the old address there, and sign in with the current one.

If the address belongs to a former employer. A Managed Apple Account shows as a separate entry in Internet Accounts. Remove it there; it is not connected to your personal Apple Account.