Does anybody know why I can not create customer credit notes?

Let's go through some troubleshooting steps together to resolve the issue you're facing when creating a credit note, admin382.

Before anything else, can you please share the error message you encountered when creating a credit note?  Also, can you outline the steps you followed to create it? Any additional information or screenshots would be helpful in providing an accurate solution.

In the meantime, let's begin by clearing your browser's cache to refresh your website's settings. While browsers store files to speed up loading, an outdated cache can slow down performance. You can also use supported browsers to optimize your QuickBooks experience.

Once done, create a credit note again.

For future reference, you can create and send customer statements to show the summary of their invoices, payments, credits, and balances.

Let us know in the comments below if you need further assistance.