If ONRR underbills a purchaser under a royalty oil contract because of a payor's underreporting or failure to report on Form MMS-2014 pursuant to Sec. 1210.52 of this chapter, the payor will be liable for payment of such underbilled amounts plus interest if they are unrecoverable from the purchaser or the surety instrument related to the contract. [58 FR 64902, Dec. 10, 1993]