Hi there, wu2838.

The option to automatically change the payment terms for the past invoices is unavailable in QuickBooks Desktop. You'll need to manually open per invoice and change the Terms in the transaction.

For more details about payment terms, you can check out this article: Set up payment terms.

I also found a helpful article for more details about adding Past Due stamp on invoices: Show Past Due stamp on invoices.

You can always visit the Community if you need anything else. I'm here to help.