Good day, Leo11,
I'm here to help ensure you're able to remove a payment term in QuickBooks Online (QBO).
While there isn't an option to permanently delete payment terms, QBO allows you to hide them. To do so, you need to open the Terms page and make the one you don't want inactive.
I'm glad to show you how:
Check out the How to Adjust Invoice Payment Terms in QuickBooks Online to learn how long you want customers to pay what they owe.
Let me know if you need additional information, and I'm always around to help you out.
Thank you and stay safe!