Legal Definitions - matching-acceptance rule

The matching-acceptance rule, also known as the mirror-image rule, is a fundamental principle in contract law. It dictates that for a valid contract to be formed, an acceptance of an offer must precisely match the terms of the original offer, without any modifications, additions, or conditions. If the acceptance introduces new terms or changes existing ones, it is not considered an acceptance but rather a rejection of the original offer and a new counter-offer. This counter-offer then requires acceptance by the original offeror.

Here are some examples to illustrate this rule:

• Example 1: Real Estate Transaction

  A homeowner offers to sell their house for $500,000, stating the sale includes all existing appliances. A potential buyer responds, "I accept your offer of $500,000, but only if you replace the refrigerator with a new stainless steel model." Under the matching-acceptance rule, this is not an acceptance. The buyer's response introduces a new condition (replacing the refrigerator), which changes the terms of the original offer. Therefore, no contract is formed, and the buyer's response is considered a counter-offer that the homeowner can choose to accept or reject.

• Example 2: Service Agreement

  A graphic designer sends a proposal to a client offering to create a new company logo for a flat fee of $2,000, with a delivery date of four weeks. The client replies, "I agree to your $2,000 fee for the logo, but I need it delivered in two weeks, not four." This response does not constitute an acceptance under the matching-acceptance rule. The client has altered a material term of the offer (the delivery timeline). Instead of forming a contract, the client has made a counter-offer, which the graphic designer is now free to accept, reject, or further negotiate.

• Example 3: Online Purchase with Modified Terms

  An online retailer lists a specific laptop for sale at $1,200. A customer adds the laptop to their cart and proceeds to checkout, but in the "special instructions" box, they type, "I agree to buy this laptop for $1,200, but only if you include a free extended warranty." Even though the customer agrees to the price, adding the condition of a free extended warranty means their response is not a mirror image of the retailer's offer. According to the matching-acceptance rule, this is not a valid acceptance, and no contract for the sale of the laptop with a free warranty is formed unless the retailer explicitly agrees to the new term.