I have determined that I should be using the Suppliers Order Number as the reference number on the payment template when I am paying an Invoice. This ensures that the Remittance Advice Slip shows the suppliers reference number.
However, when I was looking up how to make purchase invoice numbers increment as I have been using the reference number to number my purchase invoices. However according to this topic Invoice numbering I am supposed to be using the suppliers order number for the reference and not my purchase invoice number. If this is the case, then what is the purpose of having two reference numbers on the payment template. The second reference number on the RHS puts the order number on the Remittance Advice slip. The first reference number is whatever I put on the purchase invoice reference number.
Are we not supposed to be creating invoice 1, invoice 2, invoice 3 etc? This is the way PO numbers work, so not sure why this does not apply for invoices?