Maryland Code, Business Regulation § 12.5-103

(1) bona fide sales demonstrations to locksmiths or locksmith suppliers by sales representatives who are not licensed;

(2) emergency opening services by members of police departments, fire departments, or other government agencies in their official line of duty in order to protect against loss of life or property;

(3) the acquisition, making, or use of any key duplication or key blanks;

(4) the replacing of a removable or interchangeable core or recombinating a cylinder in a lock that was specifically designed by the manufacturer to be changed by the end user by use of a key;

(5) the installation, repair, replacement, or rebuilding of a lock by the manufacturer of the lock;

(6) the installation, repair, replacement, or rebuilding of an automotive lock by an automotive repair and service facility, the lock manufacturer, or the manufacturer's agent;

(7) the installation of locks by building trades personnel on projects that require a building permit;

(8) the installation or replacement of locks by a retailer or the retailer's agent:

(9) the installation or replacement of locks by a security systems technician who is licensed under Title 18 of the Business Occupations and Professions Article; and

(10) the installation, repair, replacement, rekeying, or adjusting of locks or lock components for property by an employee or agent of the property owner or a management company.