Parties such as marketers that are required to transfer assigned RINs with renewable fuel are not required to align the number of gallon-RINs transferred with the number of gallons transferred for every transaction.
Rather, the regulations require only that the number of assigned gallon-RINs (with a K code of 1) transferred with each gallon of renewable fuel be no more than 2.5. See regulation Section 80.1128(a)(4) and preamble discussion at page 23939, column 3.
Within this limit, a marketer is free to allocate gallon-RINs to volumes of renewable fuel in whatever way he chooses, so long as an end-of-quarter check on the balance of RINs versus renewable fuel in inventory is met. See regulation Section 80.1128(a)(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)