There could be several reasons for this issue. We’re not able to see exactly what’s causing this error but some of the most common reasons are:

– incorrect postcode;
– incorrect verification code or card details;
– insufficient funds / expired card;
– declined due to an international purchase (check if this feature is available for your card);
– declined by the bank.

We always recommend that you get in touch with your bank to clarify why your transaction cannot be verified.