Every organisation using Direct Debit is inspected and vetted by the banks before they’re allowed to collect your money. The banks are responsible for money being refunded if things were to go wrong, so you can bet they’re very thorough.
That said, we know you want to be completely confident that you and your hard-earned money are in safe hands (after all, the cash is being collected from your bank account) and that’s why we have the Direct Debit Guarantee. The Guarantee applies to every single Direct Debit, protecting you just in case someone makes a mistake, like collecting your money on the wrong day or taking the wrong amount.
What the Guarantee doesn’t do is affect the contract you have with a biller. For example, if you make a monthly payment for a mobile phone, and the biller takes the wrong amount, you can claim that money back but you will still owe the biller for the calls you’ve made and the data you’ve used, or for the amount you agreed to pay.
Here’s the formal bit: