Md. Code, Business Regulation § 12.5–301

Each licensed locksmith shall include on each invoice or receipt for services the following information regarding each service call:

(1) the address where the services were provided by the locksmith;

(2) the type of lock being serviced;

(3) the vehicle identification number, if applicable;

(4) the quoted cost of the service provided to the customer prior to agreeing to provide the service; and

(5) the actual cost of the service paid by the customer.