Alcohol merchants (N = 331) completed a cross-sectional survey assessing their attitudes and beliefs about underage drinking, its likely consequences, requirements for responsible beverage service (RBS) training, and performance of RBS practices and checking IDs. Merchants requiring more rigorous RBS training (i.e., state-approved vs. in-house or none) have stronger beliefs that outlets who sell to minors will get cited and that their employees know RBS practices. Also, merchants who engage in more RBS practices require more rigorous RBS training, and believe more strongly that outlets who sell to minors are more likely to face, and deserve, stricter sanctions. Merchants who check IDs more strictly conduct more RBS practices and believe more strongly that underage drinking is serious and will result in stronger consequences if caught selling to minors. These findings about the attitudes, practices, and enforcement of alcohol merchants suggests ways communities can better target their limited resources to prevent underage drinking.