Md. Code Ann., Tax-Gen. § 11-501 — § 11-501

(a) A buyer who fails to pay the sales and use tax on a purchase or use subject to the tax to the vendor as required in § 11–403 of this title or to a marketplace facilitator as required in § 11–403.1 of this title or who is required by regulation to file a return for a purchase or use subject to the tax shall complete, under oath, and file with the Comptroller a sales and use tax return:
(1) on or before the 20th day of the month that follows the month in which the buyer makes that purchase or use; and
(2) for other periods and on other dates that the Comptroller specifies, by regulation, including periods in which the buyer does not make any purchase or use subject to the sales and use tax.
(b) The return shall state for the period that the return covers:
(1) the total value of the tangible personal property, digital code, digital product, or taxable service that is subject to the sales and use tax; and
(2) the sales and use tax due.