An “autograt” (automatic gratuity) is a gratuity (or “tip”) that is automatically added to a bill, rather than a gratuity given at the customer’s discretion. Many restaurants add an “autograt” to parties of six or more people.
 
“Auto grat” was cited in print in August 1998 and “autograt” was cited in print in September 1998.
 
 
Wikipedia: Mandatory tipping
Mandatory tipping (also known as a mandatory gratuity 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.[2] Some economists have argued that tipping is economically inefficient, and suggested that mandatory gratuity might solve some of this issue.
 
Wiktionary: autograt
Etymology
Shortened auto- +‎ gratuity.
Noun
autograt (plural autograts)
1.(informal, rare, neologism) A gratuity automatically added to a bill.
     
Google Groups: rec.food.restaurants
Tipping #2
Reber
8/17/98
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If a guest that had an auto grat mentions anything negative about the service, the grat will be refunded (if not the whole meal.)
 
Google Groups: phi.food
Opinions on tipping situation
Michael P. Hally  
9/14/98
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20% of total including tax is excessive for an auto grat.
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hillary gorman  
9/16/98
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No, you shouldn’t hate not getting a good tip if you don’t add the auto-grat. You should still get a good tip without the autograt if your customers are civilized people, and your work is good! If your customers don’t tip appropriately, my opinion is ask them if your work was ok, if they act like they did nothing wrong and say everything was fine, well - auto-grat them next time they come in, as they are obviously barbarians, so to speak.
 
Urban Diner
December 1, 2004 / 2:57:52 PM
autograt
an autograt is an automatic gratuity of usually 15 to 20 percent assessed to larger tables, usually of 6 people of more. an autograt affords the waiter the luxury of knowing his/her tip is a fait accompli. some diners tip on top of autograts
 
Waiter Rant 
Tuesday, February 01, 2005
Cheap Bastards
(...) 
When I work banquets where the bqt. manager and head chef get tipped out, I walk with about 11.75% of a 20% auto-grat. That hurts.
posted by Anonymous : 2/02/2005 2:17 AM
   
Double-Tongued Dictionary
by dragonet2 15 Sep 06, 0258 GMT
autograt
n. a tip that is included as a charge on a restaurant bill rather than left to a diner’s discretion
Etymological Note: From automatic gratuity.