Xero Error: Bad request. A validation exception occurred - Credit Note # must be unique

Problem

Posting On Account sale to Xero produces an error.

Setup

  • Vend for Mac or PC
  • Xero

Cause

There's another On Account sale with the same receipt number that has already been posted to Xero. 

Solution

Void and recreate the sale.

Additional Information

Voiding Sales Using the Vend Sales Ledger 

How to recreate a sale