When planning an on-line shop, or including some payment system within a service site, careful consideration must be given to selecting the payment gateway.
"I will use the one my bank provides"
That is not always the best solution, for reasons of time/cost in implementation, quality of service and cost per transaction. The line of least resistance may prove to be the most costly in the long run. You may also consider alternative payment systems, like PayPal, WorldPay and Google Checkout.