Issuing a refund for an Invoice that has been paid will depend on how the client paid the Invoice.
If your client paid the Invoice using their credit or debit card, the payment was processed through Stripe. In this case, the refund would need to be issued through your Stripe account.
If you have any questions about the processing of this refund please contact Stripe support directly.
If your client paid via a direct transfer (ACH bank transfer, Wire transfer, Found-to-Found transfer) into your Found account you can send them back a payment from your Found account. In your Found account, you can click the ‘Send Money’ option and select ‘Pay a person or business’ to send an ACH bank transfer payment out of your Found account back to the client.