This is a preference you can activate to prevent Sales or Purchases from being exported to MYOB if it already has a document same that matches the Invoice or Purchase Number. This will ensure you do not end up with duplicated documents.
How to enable this option:
Under the Configuration screen --> Export Settings --> Transactions you will find a section called Search Previous Exports.
It has two options:
Invoice Number Lookup | If ticked then you will be warned if an invoice you are about to export matches an invoice in MYOB so that you don't end up with a duplicate. |
Purchase Order Lookup | If ticked then you will be warned if a purchase order you are about to export matches an invoice in MYOB so that you don't end up with a duplicate. |
See also:
Export Settings - Transactions
How can I mark transactions as exported in Connectwise to avoid posting them to MYOB