GoCardless is a bank-to-bank payment method. It uses Direct Debit to collect payments automatically from your customer’s bank account. Your customer needs to enter their bank details once, through a secure online form, and that's it. You’re now authorised to collect all future payments without further action from your customer. The amount you charge and when you charge can be fixed or flexible. In fact, it’s linked to the amount and due date on the QuickBooks invoice you’ve sent your customer.