> You do NOT have to pay a "minimum service fee". This is the third time I've read, recently, someone from Europe say that and it's totally false.
I did not make that up: I visited New York a month ago, and experienced first-hand what happens if you pay less than 15%. I was at a restaurant where the noise was so loud I could not talk normally with my family. The place was very loud by itself, but at a neighboring table three guys were having an aggressive argument, they were screaming, standing upright at their table, acted completely obnoxious and extremely loud. The personnel let this go on for more than 20 minutes until one guy left, angrily. The whole experience was very unpleasant for us, so I gave only $5 tip, instead of the $15 that was the "minimum". I even explained the reason. I still was told that I had miscalculated, that they could not help the behavior of other customers, and I had to get into an argument and get help from another waiter before making my way out.
Probably this was just a poorly-run restaurant, but in my experience almost all restaurants there make it quite clear on the bill that the 15% service fee is really not optional. Only the part above that is.