If any corporation is required under this chapter to file a declaration of estimated tax for any taxable year at any time on or before the fifteenth day of the tenth month of the taxable year and the corporation fails to file any declaration, although the declaration may otherwise be late, on or before that date, there shall be assessed as a penalty against the corporation an amount equal to five percent (5%) of the tax imposed upon the corporation for the taxable year. The tax administrator may waive the penalty, if it is shown to his or her satisfaction that the failure to file the declaration was due to reasonable cause and not to willful neglect.
R.I. Gen. Laws § 44-26-8