A mandatory gratuity (also known as mandatory tipping or an autograt) is a tip which is added automatically to the customer's bill, without the customer determining the amount or being asked. It may be implemented in several ways, such as applying a fixed percentage to all customer's bills, or to large groups, or on a customer-by-customer basis. Economists have varied opinions on the issue of mandatory tipping. Arguments against mandatory tipping include higher food price at the restaurant to make up for wages and loss of control of dining experience.

Some bars in New York City's borough of Manhattan have instituted mandatory tipping. Mandatory tipping is considered an oxymoron, as tipping is by definition a voluntary act on the part of the customer. The BBC has reported that some find the practice bothersome; particularly those who are not aware that the tipping is used to subsidize the sub-standard pay at the workplace. One waiter in London, England has criticized the low wages to the popular press.

Mandatory tipping and voluntary tipping are illegal in some cases: Australian casino employees, and US government employees, for example. Tipping is not generally part of Japanese culture, and can be confusing or offensive. Tipping in China is frowned upon, except for those living in the semi-westernized regions of Hong Kong and Macau.

Slightly less authoritative sources are appellate court decisions, with the U.S. Supreme Court at the top. Appellate courts regard mandatory gratuities as income for servers rather than a tip, thus affecting taxation. However, court cases have yet to set a precedent that failing to pay "mandatory gratuity" is illegal.^{[citation needed]}

Restaurant customers who pay the food portion of their bill but not the mandatory gratuity have at times been arrested, but charges are generally dropped.

Some cruise lines charge their patrons $10/day in mandatory tipping; this does not include extra gratuities for alcoholic beverages.

In her 2005 book Miss Manners' Guide to Excruciatingly Correct Behavior, Judith Martin opines that fast food restaurants will never charge mandatory tipping for their customers, despite the presence of tip jars, and considers tipping for non-table services to be inappropriate.

Ian Ayres, Fredrick E. Vars & Nasser Zakariya published a paper suggesting that tipping contributed to racial prejudice, since ethnic minorities would often be less able to pay a large tip. Another paper by Yoram Margalioth of Tel Aviv University argued that there was a negative externality associated with tipping, and that the practice facilitated tax evasion. Two other American studies have contributed to the thesis that tipping is racially discriminatory, finding that ethnic minority servers and taxi drivers received lower tips on average than their white counterparts, by both white and minority customers. In the study of the servers, an attempt by the author to isolate other possible contributing factors, such as poor service, found that "After controlling for these other variables … the server race effect is comparable across customer race."