Under Illinois law, an acceptance occurs if the party assented to the essential terms contained in the offer (Klein v. Klein, 2017 IL App (1st) 153393-U, ¶ 23.A legally binding contract must include an offer, acceptance, consideration, and intent to create legal relations. ACCEPTANCE DATE: ("Acceptance Date"). SELLER'S INFORMATION: Seller's Signature: Seller's Name (print):. Below is a list of forms and information that may be required to complete a Request for Proposal Response. Understanding the key principles of offer and acceptance in contract law, including practical examples from case law.