R.I. Gen. Laws § 44-30-4: Accounting periods and methods.

(a) Accounting periods. A taxpayer’s taxable year for the Rhode Island personal income tax shall be the same as his or her taxable year for federal income tax purposes.

(b) Change of accounting periods. If a taxpayer’s taxable year is changed for federal income tax purposes, his or her taxable year for Rhode Island personal income tax purposes shall be similarly changed.

(c) Accounting methods. A taxpayer’s method of accounting for Rhode Island personal income tax purposes shall be the same as his or her method of accounting for federal income tax purposes. In the absence of any method of accounting for federal income tax purposes, Rhode Island taxable income shall be computed under any method that the tax administrator shall determine clearly reflects income.

(d) Change of accounting methods.(1) If a taxpayer’s method of accounting is changed for federal income tax purposes, his or her method of accounting for Rhode Island personal income tax purposes shall be similarly changed.

(2) If a taxpayer’s method of accounting is changed from an accrual to an installment method, any additional tax for the year of the change of method and for any subsequent year which is attributable to the receipt of installment payments properly accrued in a prior year, shall be reduced by the portion of tax for any prior taxable year attributable to the accrual of the installment payments, in accordance with regulations of the tax administrator.