Maryland Code, Tax-General § 11-501

(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.

(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.