Between 5-10% of the bill is an appropriate amount for customers to tip, and tipping should never be expected as a matter of course, say restaurateurs.
That's according to a poll by reservation system provider ResDiary, which asked UK restaurateurs their views on diners and tipping habits.
Almost half (47%) of restaurateurs said that tipping between 5-10% of the bill was appropriate, making that the most popular choice, compared to 32% who said that tipping 10-15% of the bill was appropriate, and less than 1% who said that tipping over 20% of the bill was ideal.
Nearly one in five (18%) of respondents said that tipping should be down to the customer, and not expected as a matter of course.
The poll results also showed that many restaurateurs find that no extra "cash tips" are left by departing customers if the establishment adds an automatic service charge to the overall bill. However, some restaurateurs also said that in their experience, diners do not know the difference between a "service charge" and a "cash tip".
Chief executive of ResDairy, Mike Conyers, explained that the results highlighted a stark contrast in attitudes to topping in the UK compared to countries such as the US, where tipping and diners adding on service charge is often seen as mandatory.
He said: "The subject of tipping is perhaps one of the most hotly-debated subjects both around the restaurant table, and amongst industry professionals. The [poll] results were interesting, not least the fact that unlike our friends in the States, tipping in the UK is still very much viewed as an ‘option' this side of the pond."
ResDiary operates in countries including the US, Australia, Norway, the UAE, Hong Kong and Indonesia, and in the UK is used by restaurants within the Houses of Parliament, the Royal Opera House, and by chefs including Martin Wishart and Tom Kitchin.
Tipping is a highly contested area. The British Hospitality Association has a code of practice on tipping, and as recently as September this year, MP Andrew Percy addressed the House of Commons, to suggest that the restaurant industry's current position was "too confusing", and that certain business owners were "creaming off tips" and service charges meant for staff, thanks to a lack of enforceable legislation surrounding the practice.