Under common law, the offerees response operates as anacceptance only if it is an exact mirrorimage of the offer. If the response conflicts at all with the terms of theoffer, or adds new terms, the acceptance is an offer is a rejection, specificallya counter-offer. Moreover, if the parties perform on a contract like this, thiswill evoke the “last shot rule” where this will constitute anacceptance of the counter-offer on behalf of the offeree. 2207(1)The UCC rejects these notions at common-law.
An “expression of acceptance” does not form acontract if it is “expressly made conditional on assent to additional ordifferent terms” 2207(1) .Therefore, if the acceptance stipulates a clause saying along the lines that”acceptance of this offer only if terms of this acceptance areagreed” there is no contractformation as the offereror (consumer) has not assented to these termsexplicitly.The UCC rejects the “mirror image rule” and willoften lead to a contract being formed even though the acceptance diverges fromthe initial offer, in order to prevent working injustices. Generally,2207(1) stipulates that an “expressionof acceptance” or “written confirmation” will act as anacceptance even though it states terms that are “additional to ordifferent from” those in the offer. Where the offeree’s response contains an”additional” term, the consequences depend on whether both partiesare merchants.
2207(2). If one of the parties is not a merchant,the additional terms does not prevent the offeree’s response from giving riseto a contract, but the additional term becomes part of the contract only if theofferor (consumer) explicitlyassents to it .See exampleIf both parties are merchantsthen the additional term becomespart of the contract automatically, unless it “materially” alters thecontract, such as a disclaimer of warranty or arbitration clause. Additionally,an explicit objection by the offeror may suffice.