Please ensure that your address, including postcode, has been entered correctly. When registering your account your address needs to be the same address as your credit / debit card's registered address. Please also ensure that your card details have been entered correctly.
During the checkout process you can change your delivery address to an alternative address, by clicking on ‘Select Address’.
If you have recently changed home addresses and have not informed your bank of the change of address, the payment will not go through. If you're certain the address you have entered is the same as the address your bank account is registered to, please get in touch with your bank for an update.