" I had an excellent experience with my trip to the airport from Pimlico.
I adjusted the pickup time forward, and the driver / Phoenix adapted to it right away and made an earlier pickup.
The driver was very courteous and competent and did a great job in London traffic to make his way to the airport.
Overall the experience was excellent.
Note that I gave the driver a cash tip upon arrival at the airport.
Note that I am a US (not UK) resident, but I checked the charity box in case it helps."