If you're experiencing an error message saying that "the postcode you supplied failed validation", this happens when your bank notifies our payment processor that your billing postcode is not an exact match. 

Please ensure that your card is registered with the correct billing address if this has changed recently. 

If you are trying to pay using an existing card on file and the billing postcode has since changed since you stored your card details, this can cause your purchase to fail. The solution is to delete any previously saved card details and input the correct billing postcode at checkout.
Alternatively, try entering the card number again and the correct postcode by clicking on "Use a new card".

Hopefully this helps to resolve the issue, but if you continue to experience this error please contact us and we'll be happy to investigate.