Apologies for an OT query but I feel there are people here who may well be able to answer this...

I have recently taken to using Addison Lee for my vehicular journeys around the capital (I don't drive) rather than a taxi account, being a bit bored with Computer Cab's additional charges and disputes over run-in fees. I just wondered whether if I pay by credit card it would be usual to give the driver a tip...

Thanks. Moderators if this goes too far feel free to move.