To sign up your visitors to make payments, you’ll need a form for them to complete. WPdirectdebit uses the basic Gravity Forms plugin for this. Gravity Forms saves the completed forms within your WordPress database and WPdirectdebit validates and filters the information on the form before passing it over to GoCardless.

You can also add fields to your form to allow your visitors to decide how much and how often to pay you, if you want to allow them that flexibility. You may also wish to add check boxes to accept terms and conditions. In the United Kingdom, you could include a field to approve Gift Aid, if you are collecting donations for a charity.

Gravity Forms is well-documented so please check out their documentation if you are unfamiliar with creating a form, form feeds, confirmations and notifications.

The types of form we are interested in fall into these categories:

• Single payment: To take a one-off payment e.g. for a simple purchase. With Direct Debit there will be a delay from the setting up of the payment to the money being paid out to you.
• Recurring payment: To set up a payment that repeats at regular intervals – weekly, monthly or yearly. Multiples of these intervals are also possible. This is useful for subscriptions or repeat donations. As with single payments, the first recurring payment in a sequence will not be taken for a few days.
• Instant bank pay (IBP): To take a one-off payment e.g. for a simple purchase via open banking (UK only for now). The chief advantage of Instant Bank Pay is that the bank account is verified ‘instantly’ and so the money is available shortly after the form is submitted. You can dispatch goods without waiting for payment.
• IBP + Recurring payment: For when you wish to combine Instant Bank Pay with setting up a recurring payment. Useful for when you want to set up a recurring payment starting immediately.

See the documentation for guidance on creating each type of form.