There are a few reasons why your contactless payment might be declined.
If your card is new, you will need to make a payment using chip and PIN before you can start making contactless payments. You may also be required to enter your PIN every so often for authentication purposes.
Make sure that the terminal you are paying at supports contactless payments. They can also sometimes be declined due to connection issues.
Check that your payment amount doesn’t exceed the contactless transaction limit or daily contactless spend limit.
If your Wirex card has been damaged, you can order a replacement card by submitting a request to the Wirex Support Team.