This message appears when you try to pay part of a customer or supplier invoice with a discount when using the VAT Cash Accounting scheme.

As a workaround, you can pay the invoice in full and enter the required discount. You then need to refund the difference. 

Pay a Supplier invoice

1. Pay the supplier invoice in full with the required discount. This creates a supplier payment (PP) transaction.
2. Post a supplier refund (PR) as follows:
   
   

   Bank A/C Ref	Choose the same bank account that you used to post the supplier payment.
   Payer	Choose the required supplier.
   Tax Code	Choose the non-vatable tax code, T9 by default.
   Date	Enter the same date as the purchase payment.
   Cheque No	If required, enter the relevant cheque number.
   Amount box	Enter the amount that is to be outstanding.

3. Press Save then Close.
4. When you pay the remainder of the invoice, allocate the payment to the refund transaction.

Pay a Customer invoice

1. Pay the customer invoice in full with the required discount. This creates a customer receipt (SR) transaction.
2. Post a customer refund (SP) as follows:
   
   

   Bank A/C Ref	Choose the same bank account that you used to post the sales receipt.
   Payee	Choose the required customer.
   Tax Code	Choose the non-vatable tax code, T9 by default.
   Date	Enter the same date as the sales receipt.
   Cheque No	If required, enter the relevant cheque number.
   Amount box	Enter the amount that is to be outstanding.

3. Press Save then Close.
4. When you pay the remainder of the invoice, allocate the payment to the refund transaction.