Hi there, Texastj. 

I appreciate you chiming on the thread with your credit concern in your QuickBooks Desktop (QBDT). Let me share insights regarding this matter.

As you still have a few credits remaining in your QBDT account, it's best to utilize every bill you make within your QBDT account. This way, you can make the most of your credits and avoid any unused credits expiring. Additionally, using your credits on each bill helps to reduce the overall cost of your transactions, which can be beneficial in the long run.

However, I recommend reaching out to your accountant. This way, they can analyze your account and review all the credit applied since it'll affect the old transactions. Your accountant knows the best course of action for you and your business. 

If you don't have an accountant, I can help you find one. Feel free to visit this page to find an accountant for your business: Find a QuickBooks ProAdvisor.

Furthermore, know more about the guidelines for refunding a customer in this article: Void or refund customer payments in QuickBooks Desktop.

Please let me know if you have questions or concerns with the credit in your QBDT. I'll be here every step of the way. You can reach out to the Community at any time. Take care!