Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
1
Open Word.
At the top right of Word, log out of Office.
Restart (not shut down) your PC, then log back into Office, does that stop the annoying notification to update your payment method.
2
If not, log into your Microsoft account on this link, check the expiry date listed on your subscription, is that listed correctly.