Tipping behavior is a vital way for waiting staff to enhance their wages, and for managers to monitor guest satisfaction. Despite its importance, there is not yet an established consensus on reasons why people tip. Our lack of understanding about tipping behavior is exacerbated by a strong reliance on studies conducted in countries that have a system of voluntary tipping (e.g., the United States). The study aims therefore at expanding our understanding of tipping behavior beyond voluntary tipping countries and more specifically explaining tipping behavior under service-inclusive pricing. Data obtained from 1458 guests in five European countries show that income and payment method are the strongest predictors of customers’ decision to tip, whereas bill size is the most robust predictor of tip amount. Results advance knowledge by suggesting that social norm theory plays a major role to understand tipping behavior in service-inclusive pricing.