Tipping is certainly not mandatory in most of the US; however it is customary in many circumstances especially for most services. Many minimal wage workers especially food servers depend on tips as part of their wage. General tip would be an average of 15-20% of the total cost, depending of course of the generosity of the customer.
Tipping practices may vary depending on locations in the US and even guides and travel books offer different rates and sources. It is not common to tip at a buffet restaurant but tipping servers and wait staff that serve drinks or clear tables show good form. The rule of thumb would be to tip in proportion to the service rendered and quality of service. Tipping is a means to acknowledge good service.
Customers are required to pay tips if these are disclosed (on the menu or elsewhere) prior to being served.
Mandatory gratuities also are used by some restaurants with large numbers of foreign customers who may not be familiar with American tipping customs, often in tourist centers such as New York City. Examine your bill to see if there is a mandatory gratuity included in the bill. Some coffee shops, bakeries and other establishments have tip jars on their check-out counters. These have become more prevalent in recent decades. Generally, those who feel a desire to reward good service will make a contribution to a tip jar. Others do not. Both are fine. Tip whatever is appropriate: if the service is poor, a small tip should be left, signaling to the server that their service was subpar.
Many hotel guests tip housekeeping staff daily $1-2/bag for staff who will handle bags, $2-5/ night for housekeeper, $5-10 for requests and parking valets $3-5, depending on effort. Staffs who offer services like drivers, waiters at sit-down restaurants, delivery persons, guides and attendants are tipped according to percentage of the bill, 15-20 % is the average, lower tip means subpar while higher tip means excellence. If you have more than one person serving you at these establishments, the percentage represents the total tip and your server will split it between the groups.
Bartenders are tipped $1/ drink, or 15-20% of the total bill. If you tip well and consistently at bars and pubs, you *might* receive a drink on the house, known sometimes as a “buyback” or “comp”. This typically occurs after the 3rd drink you buy, however, is usually reserved for regular customers. Even though the drink is free, the labor isn’t. Don’t forget to tip on the “buyback.”
In most large restaurants in the USA, the server has to pay back a portion of their tips to the bartender, busser, hostess, and food runners. A good rule of thumb is if you see people other than your server helping maintain or clean tables, serve wine, or deliver food, those people are being tipped by your server for their work. Even if you do not see additional “support staff, it is very likely that the server is paying a portion of their tips to other staff.
The exception to this general rule occurs at some restaurants for parties of six or more. 15% – 20% is often automatically charged for this read as “gratuity” or “service charge,” which means that a tip is already included. Rule of thumb when calculating a table service restaurant tip is to ignore sales tax, and, for good service, calculate 15% of the entire food, beverage, and wine bill. Add or deduct according to your service received.