49 CFR § 371.9
Rebating and compensation
November 18, 2020
(a) A broker shall not charge or receive compensation from a motor carrier for brokerage service where:
(1) The broker owns or has a material beneficial interest in the shipment or
(2) The broker is able to exercise control over the shipment because the broker owns the shipper, the shipper owns the broker, or there is common ownership of the two.
(b) A broker shall not give or offer to give anything of value to any shipper, consignor or consignee (or their officers or employees) except inexpensive advertising items given for promotional purposes.