Customer has overpaid by £70 (between 3 invoices) I have allocated the full amount and it leaves the customer with an open amount of -£70. How do I allocate the refund

Hello Becky 87, 

Welcome to the community page, 

I have put the steps for how to do the customer refund below. 

Refund your customers
1. Go to the + icon in the top right corner of the screen and create a expense
2. select the customer, the date the money left your account and expense from the debtors account- save and close
3. go back to the + icon, select credit note, fill in the customer name and amount- save and close
4. go to sales on the left side of your screen, click customers at the top of your screen and find the appropriate customer
5. click new transaction on the top right of your screen and select payment
6. on the next screen tick the expense and credit note (make sure no other transactions are ticked- save and close)