How to select a particular credit memo to apply while paying a bill

Thanks for visiting the QuickBooks Community, @bookkeeper53.

Allow me to share some insights about creating a credit memo in QuickBooks Online (QBO).

We can create a credit memo in QBO when customers:

• paid more than the owed amount.
• returned the product
• requested for a refund
• received rewards as store credits

Also, we can only apply credit memos while receiving payments.

You can check these articles for more insights about the credit memo:

• Create a Credit Memo.
• Enter and apply a credit memo or delayed credit.

For reference, you may check out this link about paying bills: Enter and pay bills.

Let me know if you have other questions. I'll be right here to help you out. Have a great day!