43 CFR § 3216.15
When must I file my transfer request?
June 11, 2020
(a) File a request to transfer record title or operating rights within 90 days after you sign an agreement with the transferee. If BLM receives your request more than 90 days after signing, we may require you to re-certify that you still intend to complete the transfer.
(b) There is no specific time deadline for filing estate transfers, corporate mergers, and name changes. File them within a reasonable time.