We've hired a driver to take us from LHR to Lewes, and we've also hired a blue badge guide in Canterbury to drive us to Leeds Castle, guide us there, and return us to Canterbury. We've read that tipping is quite different in the UK, so we'd appreciate suggestions on what percentage of their fee we should tip them. Also, are they likely to have credit card machines or should we plan to have pounds on hand to pay them in cash? Thank you.
You don’t have to tip them anything but if you really can’t stop yourself 5% is likely to be enough
Tipping is indeed quite different in the UK compared to North America. As kernel says you really do not need to tip at all. If you get outstanding service feel free to give a modest amount if you must.
Whilst we are nearly cash free in the UK I think I would be inclined to offer cash if you really want to. I can't see a guide carrying around the means for contactless payments, assuming you have already paid his fee?
both of them have set the price for what they will do. You don't have to add anything. Of course you can add if you really need to.
About the credit card - won't you be paying them up front, online, before you meet them?
Either of them could use their phone for payment, or have a small credit card sized device which works with the phone for payment, or they may expect cash. Have you asked?