Because some pay-at-pump machines charge a final amount a few days after the first transaction, your account could be charged an amount that’s more than your current balance.
This could result in your balance being reduced to a negative figure, which is called an unauthorised overdraft. You would then be unable to use your card until the negative balance was cleared.
We want to make sure that you’re always able to use your card, so we may decline pay-at-pump transactions if there isn’t enough money in your account to cover the potential cost.
We’re really sorry for the inconvenience. You can avoid this problem by adding money to your account to ensure that your balance will cover the maximum potential cost of your transaction.