Md. Code, Business Regulation § 17-1803

(a) Except as otherwise provided in this subtitle, a person must have a trader’s license whenever the person:

(1) does business as a trader in the State; or

(2) does business as an exhibitor in the State.

(b) A separate trader’s license is required for each store or place of business that a person operates in the State.

(c) (1) A separate trader’s license is required for each mobile place of business that operates exclusively in one fixed location in the State.

(2) Each mobile place of business that operates in more than one location in the State requires a trader’s license and a peddler’s license issued under Subtitle 9 of this title.

(d) This section does not apply to:

(1) a grower, maker, or manufacturer of goods;

(2) a nonresident traveling salesperson, sample merchant, or representative of a foreign mercantile or manufacturing business while selling to or soliciting an order from a licensed trader in the State;

(3) a private individual while publicly selling the individual’s personal effects on the individual’s property, if the individual holds only 1 sale not exceeding 14 consecutive days in a calendar year; or

(4) a restaurant licensed under Subtitle 16 of this title that generates 10% or less of its annual sales from nonfood items.

(e) (1) An exhibitor need not get a trader’s license for a show if the show is promoted by:

(i) a church, as defined in § 5–301(b) of the Corporations and Associations Article;

(ii) a governmental unit;

(iii) an amateur radio organization;

(iv) an antique vehicle, machine, and equipment organization;

(v) a volunteer fire department or rescue squad; or

(vi) a model train collectors’ association.

(2) An exhibitor need not get a trader’s license for a show if the exhibitor gives to the promoter an exhibitor’s affidavit stating that the exhibitor:

(i) receives less than 10% of the exhibitor’s annual income from selling the kind of goods that the exhibitor will display and sell at the show; and

(ii) has not participated in more than three shows, not including participation in one show sponsored by a national organization that is exempt from taxation under § 501(c)(3) of the Internal Revenue Code, during the previous 365 days.

(3) An exhibitor at an antique show, coin show, or collector show need not get a trader’s license for the show if the exhibitor gives to the promoter an exhibitor’s affidavit stating that the exhibitor:

(i) will display and sell at the show;

(ii) receives less than 10% of the exhibitor’s annual income in the State from selling the kind of goods that the exhibitor will display and sell at the show; and

(iii) has not participated in more than three antique shows, coin shows, or collector shows in the State during the previous 365 days.

(4) An exhibitor who has a trader’s license need not get an additional trader’s license for a show if, before the show, the exhibitor gives the promoter a photocopy of the trader’s license.