Online Contracts: Concluding contracts online is dependant on the clarity of the offer and acceptance process, the nature of the contractual terms and how they are incorporated, and whether contracts agreed by email contain sufficient formality. The global nature of World Wide Web (WWW) means that parties need to consider international law issues. General Principle: Under the most jurisdictions, the formation of a contract requires the following elements: An offer; Unequivocal acceptance of the offer which is communicated to the person making the offer; Consideration; An intention to create legal relations; and Capacity in each party to be legally bound. It is recommended that the parties have written contracts, signed and retain copies of all relevant correspondence and documents relating to that contract. Offer: Offer is an expression of willingness to enter intro a contract on the stated terms. It is implies an intention that the acceptance of the terms will become a binding contract. English law distinguishes between an offer and an "invitation to treat", such as advertisement promotes the sale however it is not an offer. For more please see, Spencer V Harding (1870) L.R 5C.P 561 Under English traditional contract law, displaying a goods in a shop is not an offer but it is an invitation to treat , however, it is depend on the judge decision about the circumstances of offers and invitation to treat. See Argus case! In September 1999, due to software error, Argos displayed Sony Television set for sale on price of £3 rather than the correct retail price of 299.99. In 2002 Kodak faced a similar problem when it incorrectly advertised digital cameras for sale on its website for £100 instead of correct value of £329. Acceptance: A contract is formed when the offer is unconditionally accepted and the acceptance of the terms of one party's offer by the other party, and communication of that acceptance, concludes the contract. Two Rules for acceptance: The receipt rule: this states that a contract is formed at the time and place when the acceptance is received by the offeror. (Fax, phone) The Postal rule: this applies to communications by post, according to which acceptance is effective at the time of posting of the communication. (UK Case: Entores Limited v Miles Far East Corp  2 Q.B. 327.) If the correspondents are both online their message can be received in a matter of seconds. In this circumstance it is argued the postal rule should not apply as communication is instantaneous. Accordingly, the time of communication is largely crucial as it determines when the contract is made and the time at which the offer may no longer be revoked. However, communication over the internet is not always instantaneous, Email message and order from a website can take from a seconds to several days to arrive at destination. Due to this uncertainly, a good argument that the postal rule apply to communication of acceptance via email. Capacity: For a contract to be valid, the parties must intend to enter into the contract and have the capacity to do so. Due to anonymous nature of the internet the e-trader has limited means of checking the identity of other buyer. Legal capacity: Under English law, contract made with minors are generally voidable at the minor's option under the Minor's Contract Act 1987. Under Iran Civil law article 212, it is stated that contract with minors are voidable. Mistake: a mistake does not invalidate a contract unless it is fundamental. Some jurisdiction requires that certain contracts muse be in writing. Pretty pictures v quixote films ltd EWHC 311 (QBD) Accordingly, parties to a contract are advised to have a written copy of the contract for evidential purpose.