Unless it is expressly specified that an offer to buy or sell goods must be accepted just as made, the offeree may accept an offer and at the same time propose an additional term. This is contrary to general contract law. Under general contract law, the proposed additional term would be considered a counteroffer and the original offered would be rejected. Under Article 2 of the Uniform Commercial Code, the new term does not reject the original offer. A contract arises on the terms of the original offer, and the new term is a counteroffer. The new term does not become binding until accepted by the original offeror. If, however, the offer states that it must be accepted exactly as made, the ordinary contract law rules apply.
In a transaction between merchants, the additional term becomes part of the contract if that term does not materially alter the offer and no objection is made to it. However, if such an additional term from the seller operates solely to the sellers advantage, it is a material term and must be accepted by the buyer to be effective.
Para su conveniencia, debajo del texto en español le brindamos la versión completa de este formulario en inglés. For your convenience, the complete English version of this form is attached below the Spanish version.