Since I do not have evidence for what I had experience. Here are some advice on the net: https://www.independent.co.uk/money/spend-save/tips-on-tipping-how-and

Since I do not have evidence for what I had experience. Here are some advice on the net: https://www.independent.co.uk/money/spend-save/tips-on-tipping-how-and-when-should-you-give-extra-money-for-good-service-8570518.html https://www.independent.co.uk/money/spend-save/tips-on-tippi... https://www.lhaa.co.uk/blog/how-much-to-tip-a-hairdresser#:~:text=The%20minimum%20level%20of%20tip,around%2020%25%20of%20the%20bill https://www.lhaa.co.uk/blog/how-much-to-tip-a-hairdresser#:~.... Although it is always worded "if-you-want-to" or "if-you-can-afford". I feel this is a bit ambiguous.