To add a refund payment, open the booking record and go to the Finance tab. Click the Add new button underneath the existing payments.
From the Type drop down, you'll find a refund option for any existing payments. Select the required payment.
The Amount will auto-populate with the value of the original payment, however this can be edited if you are refunding a lower amount. Click Save to proceed.
A new payment will have been added to the Payments section on the Finance tab within the booking record and the amount will alter the booking balance accordingly.