GoCardless is basicly a DirectDebit management company such as you can do via your bank however need the volume for them to do it.
What is a DirectDebit?
You set up a direct debit by signing a Direct Debit Mandate form, which is then submited to the bank/building socity. A direct debit can be set up to pay on a particular date every month, quarter or year.
Money is then taken from your bank account automatically by the company you are paying, according to your instructions. Generally direct debits are taken on the next working day, however if you sign an agreement that the company can take the payment earlier then it is possible that they are able to do this.
The Difference between a Standing Order (SO)/BACs and a DirectDebit.
The main difference to a standing order is that the company or person you are paying can change the amount of the direct debit or the date they take it – although they must inform you of this first with a certain number of days notice.
Hope all that helps,