R.I. Gen. Laws § 44-13-15
Any tax imposed under the terms of this chapter shall be due and payable upon the last day upon which a return must be filed under the provisions of §§ 44-13-6 and 44-13-7. Upon the filing of the return, the full amount of any tax, as computed by the corporation, shall be paid to the tax administrator. As soon as practicable after the return is filed, the tax administrator shall examine it and determine the correct amount of the tax, and, if an additional tax is due, the tax administrator shall notify the corporation, and the tax shall be paid within thirty (30) days after the mailing of the notice. The failure of the corporation to receive any notice required by this section shall not relieve it of the obligation to pay any tax imposed under the terms of this chapter or any interest or penalties.
R.I. Gen. Laws § 44-13-15