QuickBooks Online sync error: String length specified does not match the supported length. Min:0 Max:21 supported. Supplied length:XX

Why the sync error occurs

This error occurs when a vendor credit in Key CashFlow is attempting to sync to QuickBooks Online, but the value in the Ref # field is greater than 21 characters.

How to fix the sync error

  1. In Key CashFlow, edit the vendor credit Ref # to be less than 21 characters
  2. Sync