What this error means
When QuickBooks detects that a document reference number already exists, you will encounter this error. QuickBooks requires each transaction reference number to be unique.
When Link My Books attempts to create a transaction with a reference number that already exists, QuickBooks blocks the request.
Why this happens
Common reasons include:
Multiple sales channels generating settlements for the same date range
Two settlements producing the same reference number
Manual transactions already exist in QuickBooks with the same reference
How to resolve it
To resolve this issue, you can contact support to enable numerical document numbering in Link My Books.
This changes the reference format so that each settlement receives a unique identifier.
If numerical references are already enabled, review the existing transaction in QuickBooks and adjust the reference if necessary.
When to contact support
Contact support if:
Duplicate reference numbers continue to appear
The duplicate reference is not visible in QuickBooks