§ 21-5. Interest and civil penalties.

(a) In general.

(1) Any person, firm, association, or corporation that refuses or fails to collect the taxes imposed by this subtitle, or to make a proper return when due, or to pay the taxes collected over to the Director of Finance when due, is liable for and must pay to the Director, in addition to the tax due:

(i) interest on the amount of tax due at the rate of 1% for each month or part of a month that the tax is overdue; and

(ii) a penalty of:

(A) if the tax is 30 to 59 days past due, 30% of the amount due;

(B) if the tax is 60 to 89 days past due, 60% of the amount due; and

(C) if the tax is 90 days or more past due, 100% of the amount due.

(2) The penalty imposed by paragraph (1)(ii) of this subsection applies to all unpaid taxes regardless of the original date on which the unpaid taxes first became due.

(b) Collection.

This interest and penalty shall be collected as a part of the tax itself.