Whenever I travel to London, I use Blacklane to get to and from the airport and to and from my hotel and/or my wife’s relatives’ house. (I also use Blacklane PASS to zip through the airports like a celeb; full disclosure: I’m one of their brand ambassadors.)
However, because Blacklane requires at least a one-hour notice ahead of a pick-up, whenever I need to get around in London, I either take the Tube or an uberX. I rarely take a hackney cab (black taxi) because they’re expensive and charge extra when you use a credit card, and I rarely carry cash these days (or at least they used to; I’m not sure if that’s still the case).
Another way to get a ride in London that I know some Londoners like is to use a website/app called Cabhit, which allows you to search a variety of taxi and cab services to instantly find a car, whenever you need it and wherever you are in England. You can even use it to pre-book a car. You simply pick the best quote that you’re offered via the taxi fare calculator and get going (and they don’t charge extra for paying with a credit card).