You can allocate transactions in your supplier's record using Account Allocation.

This allocation method creates a Supplier Allocation transaction in the supplier record and audit trail.

The transaction allows you to check allocations and unallocate them if required.

1. Go to Contacts and select Suppliers.
2. Open the relevant supplier record.
3. Search for the allocation.
   
   ▼ How to search for the supplier allocation

   Change the From and To dates to match the supplier allocation date. The allocation date is the same as the most recent transaction within the allocation.

   EXAMPLE:

   When you allocate an invoice in Sage Accounting, the allocation date matches the payment date. For example, if the invoice is dated 1 June and you pay on 15 June, the allocation date is 15 June. If you make the payment before the invoice date, Sage Accounting uses the invoice date instead.

    Change the Type dropdown to Supplier Allocation.

4. Select the allocation to open it.
5. Untick the checkbox for both of transactions in the allocation.
6. Select Save.

You've removed the supplier allocation. Invoices and credit notes are now outstanding. Supplier payments remain on the supplier's account as a payment on account.