An operating rights owner (who does not hold record title) who assigns the operating rights remains liable for all obligations of the lease that accrued during the period in which the assignor owned the operating rights, up to the effective date of the assignment, including decommissioning obligations that accrued during that period. BOEM's approval of the assignment does not alter that liability. Even after assignment, BOEM or BSEE may require the assignor to bring the lease into compliance if the assignee or any subsequent assignee fails to perform any obligation under the lease, to the extent the obligation accrued before approval of the assignment.