Payments can fail for a number of reasons, the most common one being that the customer did not have the funds available. If a payment fails GoCardless will notify you via email. The invoice will appear in the Pending section of your invoices tab and be marked as unpaid in Xero.
1). To re-try a payment, simply go to Invoices > select Pending
2). Click on Actions (three dots) next to the failed payment
3). Click Retry Payment.
We will then attempt to collect the payment as soon as possible based on the scheme timings.
If this option does not appear here, check that the customer has an active mandate in place. It is possible the customer has cancelled their mandate and you will need to ask them to complete a new authorisation form before any further payments can be collected from them.
For more information on failed payments, please read this article.