Field help (BSIPAYREF)
Select this check box to search by payment reference. The bank transaction reference must be stored in [BSIIMPD] PAYREF (bank import segment settings). Matching then compares this reference against the payment references stored in either the [PAYMENTD] NUM or REF fields.
If you select this option and a match is found, no other BP criteria are considered even if they are selected.
If the bank returns these references through the bank statement file, you should consider these as very precise matching criteria and use these matches.