R.I. Gen. Laws § 44-72-7 — Returns

(a) The tax imposed by this chapter shall be due and payable in four (4) equal installments.
The first installment shall be paid on or before September 15 of the taxable year,
the second installment shall be paid on or before December 15 of the taxable year,
the third installment shall be paid on or before March 15 of the taxable year, and
the fourth installment shall be paid on or before June 15 of the taxable year.
(b) The tax administrator is authorized to adopt rules, pursuant to this chapter, relative
to the form of the return and the data that it shall contain for the correct computation
of the imposed tax. All returns shall be signed by the taxpayer or by its authorized
representative, subject to the pains and penalties of perjury. If a return shows an
overpayment of the tax due, the tax administrator shall refund or credit the overpayment
to the taxpayer.
(c) The tax administrator, for good cause shown, may extend the time within which a taxpayer
is required to file a return. If the return is filed during the period of extension,
no penalty or late filing charge shall be imposed for failure to file the return at
the time required by this chapter; however, the taxpayer shall be liable for interest
as prescribed in this chapter. Failure to file the return during the period for the
extension shall void the extension.