Mystery shopping is a tool that involves sending consumers to places of business, government agencies, or other service providers to simulate a typical customer inquiry. By conducting mystery shopping visits, we can better understand important financial inclusion issues such as differentiated treatment of low-income or inexperienced consumers, quality of product advice, and compliance with consumer protection rules such as pricing transparency and disclosure. This Technical Guide from CGAP summarizes in an easy “how-to” manner CGAP’s experience conducting mystery shopping for a range of products. The guide provides information on how to design, execute, and analyze mystery shopping exercises for financial services. This includes descriptions of the several stages of implementing a mystery shopping program, and actual field guides such as questionnaires, shopper training materials and sales staff surveys.