Martyn's Law applies to "qualifying premises": buildings (or buildings together with adjoining land) that are accessible to the public and wholly or mainly used for one or more of the purposes set out in Schedule 1 of the Act. These uses include a wide variety of everyday locations such as: shops; pubs, bars and restaurants; nightclubs and music venues; cinemas and theatres; sports grounds; libraries, museums and galleries; halls and conference centres; visitor attractions; hotels; places of worship; hospitals and healthcare premises; bus and railway stations; airports; childcare premises; schools, colleges and universities; and public authority buildings. It also applies to "qualifying events": events with controlled public access, for example ticket checks.

Premises or events can still be publicly accessible even if access is limited to paying customers, ticket holders or members.