I used to tip in the UK, but I no longer do. In the US, waiters are just paid a retainer by the restaurant, the bill is for the food, the tip is paying the waiter and that is fair. In the UK and other countries, waiters are paid a wage. I stopped after having a conversation with my then, Spanish teacher. Somehow the subject came up and she told me that when she first came to the UK, she worked as a waiter. She said that tipping isn’t a thing in Spain, and that when she was tipped here, she felt offended, as if she was being patronised. She pointed out that she was earning a good wage and that it wasn’t necessary. That where they are paid £10 per hour, that is £1770 per month, and that many restaurants pay their staff more. She added that since hubby and I are living on pensions, it was crazy to tip. After that conversation, I have never tipped in a restaurant in the UK. That said, I still cringe when I leave without doing so!