How can I prevent duplicate transactions when changing the invoice number in QuickBooks?
The Invoice number in QuickBooks is system generated. Changing the invoice number of an existing invoice that is in the AvaTax Admin Console will cause the invoice to duplicate. Avalara AvaTax treats this as a new invoice as the invoice number is different.
Duplicate transactions can occur if there are multiple versions of AvaTax running in QuickBooks. To check this, click "Edit" > "Preferences" > "Integrated Applications".
If you find there are multiple versions of "AvaTax" in your integrated applications, you will need to remove the older version which requires you to be in Single User Mode.