Refund a WHMCS Gateway payment

[HazFlorinMarian]

Hello!

I try to issue a full refund but it fails with error shown above.

You don’t have sufficient balance to complete this payment. Add funds or add a bank account and confirm it.

What can I do?

[kernowlass]

@HazFlorinMarian 

Refunds are normally sourced from either a Paypal balance OR bank account (some countries differ).
However you need to have the full amount of the refund in your balance for that option to be used.
As Paypal no longer returns the fee you were charged when your buyer paid you may not have the full amount in your balance in which case your bank account would be used instead.