Make sure your card details are entered correctly – the security code is a three-digit number found on the back of your card. Your card issuer may have declined your payment and as we are not told the reason for this, you would need to check with them or contact your bank. Alternatively, you might want to try paying with another card. If you've tried all of the above and are still having problems, please contact our customer care team at customercare@aviela.co.uk or via our online messenger and we will be happy to help.