Reporting - Receivable and Payable Credit Note reports
Create a Receivable and/or Payable Credit Note Report which lists all credit notes issued/received, and the corresponding invoice they are linked to. This will help as when a credit note is issued the status is 'paid', however if I want to do a review of invoices and days until invoice is paid, I want to be able to exclude items that have been credit noted.

Thanks for sharing your idea.
For now, the closest thing we have is to use the Receivable/Payable Invoice Detail (or Summary) reports.
You can use the Filter option on Source, to only show credit notes. However, the existing reports don't show the invoices/bills they're allocated to.
It's now up to the community to get behind and support it. Make sure you share your idea with any colleagues that this could benefit so they can add their vote too!
Along with votes, other members can now comment to share additional detail about how your idea could improve their experience with Xero.