To delete a supplier invoice simply going to Purchasing > Supplier (search for the supplier name) > Actions > Delete > Invoices. Then click the little red cross next to the supplier invoice.
If the invoice doesn't appear in the list there are two reason:
- It isn't an invoice! In this case, please make sure the record actually has an invoice number. If it doesn't then it is like that it is a purchase order (without an invoice number) and therefore will show up under Actions > Delete > Unassigned Parts.
- The invoice has already been sent to your accounting package like SAGE/Quickbooks etc. In this case there is no way to delete the supplier invoice.