I changed my payment method, but late payment didn't process and I'm unable to access MS Office.

This usually happens when the subscription is still past due even after the payment method was updated, or the payment was not completed against the correct subscription.

Try this:

1. Sign in to Services & subscriptions at https://account.microsoft.com/services with the same Microsoft account that owns the Microsoft 365 subscription.
2. Find the subscription and check whether it shows past due, expired, or suspended.
3. Select Pay now for the past-due subscription.
4. Review the payment method shown there. If needed, update the expiration date or add a new payment method, then select Next to complete the payment.
5. If the subscription already shows active, sign out of Office and sign back in with that same Microsoft account.

If Office shows “Account Notice: We’ve run into a problem with your Microsoft 365 subscription”, that notice is often caused by a subscription payment problem such as a declined, expired, or canceled card. If nothing is done, Office can go into reduced functionality mode, where documents can still be opened and printed but not edited or newly created.

If the payment method was changed but the charge still did not go through, also check:

• the card details exactly match the card statement information
• the card has sufficient funds
• the bank is not blocking the transaction because of fraud/security checks

If the subscription was bought through a third-party retailer, payment changes must be managed through that third party.

If the subscription still remains inaccessible after completing Pay now, use Contact Support through Microsoft Support.

References:

• Pay for a past-due Microsoft subscription
• A subscription notice appears when I open a Microsoft 365 application
• Troubleshoot payment option issues