By design or a quirk of nature we have some customers who end up with an amount in Liabilities/Customer credits.
This is easily handled if I sell to that customer some further products or services, as the credit is applied to the new invoice amount.
However, if I just wish to pay the money back to the customer, by creating a credit invoice, then just paying from the bank account, I seem to be running into problems.
I can’t specify ‘customer credit’ account on the invoice line item.
I could probably ‘spend money’ from the cash account and allocate it to the customer credit, but I want to show the transaction on an invoice so that the customer knows what I have paid him back for.
Based on still having a Customer credits account, you are thousands of versions behind. Update your software. Customer credits was integrated with Accounts receivable in July 2016. See [16.7.73] Categorization against customer and supplier accounts more intuitive.
Spend Money transactions were also long ago replaced with payments.
When you update, all your data will be converted to current standards. The same capabilities, and many more, are available.
What used to show as a liability in Customer credits will now be a negative contribution to Accounts receivable. If a customer wants a refund, you don’t enter that with a credit note. A prior credit note is probably why they have a credit balance. You just enter a payment, allocated to Accounts receivable (after the update). Read the Guide: Pay a refund | Manager.