Instead of receiving invoices from your suppliers, you can use SupplyOn to issue credit notes. These are based on the agreed prices as well as the quantities delivered. The credit-note procedure not only saves you from having to check invoices internally but also saves your suppliers having to produce and send out the invoices in the first place. You can also effect payment as soon as you send out a credit note.
SupplyOn offers you the option to process Self-Billing Invoices either via classic EDI or WebEDI.