Hello Tommie Veldman 

Thank you for reaching out to us. If the supplier accounts are open items, you can use the Process Match Open Item screen to check for any unallocated payments and match them to any outstanding invoices.

This article explains the procedure: How do I match and unmatch open item

Please let me know if you have any further queries.

Otherwise please confirm with me if the answer was helpful: By clicking on Verify answer.

Jan