Md. Code Ann., Tax-Gen. § 9-323 — § 9-323

(a) Except as provided in subsection (b) of this section, a license or an exemption certificate expires on the first May 31 after its effective date.
(b) A Class “G-Temporary” license expires on the earlier of:
(1) termination of the contract for which the license was issued; or
(2) the first May 31 after its effective date.