Credit Card Booking Fee

[Affluence!]

hey guys just need some advice, i am working for a language school, at present the fee for paying when making a credit card booking is included in the course fee, we would like to change this so that the fee for a credit card booking is seperate, like ryanair, aer lingus etc... is this legal and what are the implications, where would i find more info etc? thanks for the help!