By the hour or by the route
A point-to-point transfer is billed for the pick-up and the run from A to B. Hourly hire is billed for the time the car is reserved for you: it waits at the entrance while your meeting runs, then goes wherever you say next.
A practical rule: up to two trips a day is cheaper point-to-point, three or more is cheaper by the hour. Describe your day and the dispatcher will price both.
Day and multi-day hire
A business day is 10 hours with one chauffeur at a flat price, with each extra hour at the hourly rate. It fits visit programmes: airport meet, hotel, negotiations, lunch, a trip out of town, dinner, return. For several consecutive days we assign one chauffeur and one car, so nothing has to be explained twice.
Beyond 12 hours, and on long-distance routes, we add a second chauffeur — a safety requirement, not a way to raise the invoice.