Handling fee for a payment?

Hello,

Does anyone know whether it is possible to add a handling fee for a particular payment module? I am thinking to add a $5 fee for COD, and I guess this should be a common use case.

Thanks.

This is something that is normally built into the payment module itself. Some of the SagePay mods for example can add a credit surcharge. However, there's nothing like this built into COD.

Any particular suggestion of how we can add it to COD?

What I can think is kind of a hack: basically create a product called "COD surcharge". And at the payment selection page, if customer select COD, I just add this product to cart, else, I just remove it from cart (if it is there). Since this is a standard product, so I assme the change to cart class (or other core parts) should be small. The only change will be the select payment page module.

I'd look at adding a new order total class that's only brought into effect when the payment module is COD. But I don't have anything more specific as I've not actually done this myself.