29 CFR § 1904.30 - Multiple business establishments.
(b) Implementation—(1) Do I need to keep OSHA injury and illness records for short-term establishments (i.e., establishments that will exist for less than a year)? Yes, however, you do not have to keep a separate OSHA 300 Log for each such establishment. You may keep one OSHA 300 Log that covers all of your short-term establishments. You may also include the short-term establishments' recordable injuries and illnesses on an OSHA 300 Log that covers short-term establishments for individual company divisions or geographic regions.
(2) May I keep the records for all of my establishments at my headquarters location or at some other central location? Yes, you may keep the records for an establishment at your headquarters or other central location if you can:
(i) Transmit information about the injuries and illnesses from the establishment to the central location within seven (7) calendar days of receiving information that a recordable injury or illness has occurred; and
(ii) Produce and send the records from the central location to the establishment within the time frames required by §§ 1904.35 and 1904.40 when you are required to provide records to a government representative, employees, former employees or employee representatives.
(3) Some of my employees work at several different locations or do not work at any of my establishments at all. How do I record cases for these employees? You must link each of your employees with one of your establishments, for recordkeeping purposes. You must record the injury and illness on the OSHA 300 Log of the injured or ill employee's establishment, or on an OSHA 300 Log that covers that employee's short-term establishment.
(4) How do I record an injury or illness when an employee of one of my establishments is injured or becomes ill while visiting or working at another of my establishments, or while working away from any of my establishments? If the injury or illness occurs at one of your establishments, you must record the injury or illness on the OSHA 300 Log of the establishment at which the injury or illness occurred. If the employee is injured or becomes ill and is not at one of your establishments, you must record the case on the OSHA 300 Log at the establishment at which the employee normally works.