43 CFR §3281.9

1. (a)The unit operator must provide documentation to BLM of the commitment status of each lease and tract in the designated unit area. The documentation must include a joinder or other comparable document signed by the lessee or mineral rights owner, or evidence that an opportunity to join was offered and no response was received (see § 3281.8).
2. (b)A majority interest of owners of any single Federal lease has authority to commit the lease to a unit agreement.