AvaTax is using the QuickBooks Online internal ID as part of the AvaTax document code. It is unclear how to find matching documents in QuickBooks Online with this ID number.
- Go to any document of the same type (invoice, estimate, credit, etc.) in QBO.
- In the web address (URL) on your browser it will say something like ".../invoice?txnId=23". Change the number to match the internal ID you are looking for and press enter.