The British do not tip. I had a friend visiting from the U.K. and she took a taxi and the fare was $12.50. She gave the driver $13. She was surprised that my mother and I were aghast at this. She even mentioned that she usually didn't tip in the U.K.
When we went out to eat, her mother always asked us how much to tip.
Likewise, when I was in the U.K. and before I got word about the tipping policy, I had tipped 20% at a restaurant. I later realized why the server had been so happy.
I do like like the automatic tipping though. For instance, I do not tip the head waiter. A friend who works for RC told me that it wasn't necessary to tip the head waiter unless s/he did something extra for me. Automatic tipping would mean I would have no choice as to whom I tip.
I do tip the prescribed amount for waiter, assistant waiter, and attendant.