QuickBooks Online Sync Error: You must specify a different number. This number has already been used.

Why the Sync Error occurs

This error occurs when the reference number (Ref#) on a Bill.com offline payment is already in use within QuickBooks Online or has been entered on a payment that is for more than one invoice.

How to Fix the Sync Error

Void the offline payment and record a new offline payment with the correct reference number.

  1. Click the payment confirmation number from the sync status page
  2. Click Void payment
  3. Click Yes to confirm

Record a new offline payment for the bill(s).

Alternatively, record the payment manually in QuickBooks Online and contact Customer Support to request the sync error be cleared.