I credited the invoice that had already been paid. How can I refund the customer in Sage and allocate this payment against his next invoice? Is it correct to go to Customer Writte Off/Refunds and choose the invoice I want to refund? Shall I put in additional reference section the new invoice number that the payment is going to be allocated too? And how can I issue him a refund note ?
Thank you for your answer I think you are right. In customer activity report is shown that the invoice is paid and I credited it as I put a wrong product code but the reissued-correct invoice is for the same value. So on the other hand it balances. I think I should customer explain the situation as it may cause some confusion....