Legal Question in Business Law in Illinois

Technically the person whose signature is required on a document is the person who must sign a document. In the "old days" if a person was illiterate or unable to write for some other reason, they might put an "X" for their signature and have a witness attest it was their signature, which is actually one main reason why the idea of having "witness" signatures on documents got started in the first place. Technically a person can authorize another person to apply a "rubber stamp" signature but that can be risky. Otherwise, the "safest" way for one person to be authorized to sign things for another person is under a statutory power of attorney.