A party may transfer any volume of renewable fuel to any other party without simultaneously transferring any assigned RINs to that same party.
However, assigned RINs can only be transferred to another party in association with the transfer of a volume of renewable fuel. Under regulation Section 80.1128(a)(4), the ratio of assigned RINs transferred to gallons transferred can be anywhere between zero and 2.5.
Question and Answer was originally posted at: Questions and Answers on the Renewable Fuel Standard Program (PDF) (55 pp, 221 K, EPA420-F-07-041a, August 2007, About PDF)