R.I. Gen. Laws § 44-18-33: Sales to common carrier for use outside state.

There is exempted from the computation of the amount of the sales tax the gross receipts from sales of tangible personal property to a common carrier, shipped by the seller via the purchasing carrier under a bill of lading whether the freight is paid in advance, or the shipment is made freight charges collect, to a point outside of this state and the property is actually transported to the out-of-state destination for use by the carrier in the conduct of its business as a common carrier.