Xero sync error: A validation exception occurred. The invoice you are trying to allocate to has already been paid off Credit Note cannot be allocated as amount is greater than amount outstanding
Why the sync error occurs
This error occurs when a credit and/or payment is trying to sync to Xero, but a payment or credit is already applied to the bill in Xero.
How to fix the sync error
- In Xero, verify that nothing has been applied to the bill
- If a payment or credit has been applied, unapply it in Xero
- Sync again
If the error persists or if you don't need the payment to sync, please contact Customer Support.