R.I. Gen. Laws § 28-43-15: Interest on delinquent payments.

Employers who or that fail to make payment of contributions as required by chapters 42 — 44 of this title or by the regulations adopted as prescribed shall be liable to the employment security interest fund for interest on the outstanding balance of those delinquent payments at the rate of one and one half percent (1.5%) per month from the date the payment became due until paid.