tipping etiquette

Tipping etiquette refers to the social conventions governing when, whom, and how much to tip for services.

These norms vary widely by country, industry, and establishment—what's expected for a restaurant server differs from a hotel porter or hairdresser.

In the United States, where service workers often depend on tips for income, tipping etiquette carries more weight than in countries where it's optional or even refused: I'm never sure about tipping etiquette at coffee shops.