What happens if a direct debit payment fails? How do I track failed payments?

By default, the direct debit payments system does not retry failed payments. 

Payments by direct debit are tried only once. You, (the centre admin or staff with billing access) can view the event details and the exact reason for payment failure by logging in to the GoCardless dashboard.

You can then contact the bill payer to make a payment via a manual direct debit transaction (initiated by the bill payer).

When the billpayer is ready to settle a failed payment, they can simply click on the 'Pay Now' link received via email along with the last issued invoice and make the payment.  They will be taken to a page that shows their live account balance amount as on date.

The failed status can be tracked using the 'Online Payments Dashboard'.