Ill. Sup. Ct. R. 5.4
Comment
[1] The provisions of this Rule express traditional limitations on sharing fees. These limitations are to protect the lawyer's professional independence of judgment. Where someone other than the client pays the lawyer's fee or salary, or recommends employment of the lawyer, that arrangement does not modify the lawyer's obligation to the client. As stated in paragraph (c), such arrangements should not interfere with the lawyer's professional judgment.
[2] This Rule also expresses traditional limitations on permitting a third party to direct or regulate the lawyer's professional judgment in rendering legal services to another. See also Rule 1.8(f) (lawyer may accept compensation from a third party as long as there is no interference with the lawyer's independent professional judgment and the client gives informed consent).