This error could happen for many reasons including:

1) Insufficient funds

2) 3D secure authentication error

3) Wrong card details entered

4) Bank temporarily blocked your card

5) Bank believes transaction is possible fraud and blocked it.

Before contacting your bank try making your payment again and choose our alternative card processing service on the iFastNet invoice payment screen which is :

Card / Gpay / ApplePay

Or PayPal if you have a PayPal account.

Finally if all of the above does not work try using a different card or contact your bank to ask why your payments are being declined.