What characteristic is essential for a legally binding contract?

A legally binding contract requires mutual assent, which refers to the agreement of both parties to the terms of the contract. This means that both parties must understand and agree to the contract's terms, expressing their willingness to enter into the agreement. The concept of mutual assent is often encapsulated by the phrase "meeting of the minds." This characteristic is foundational for all contracts, as it establishes a clear understanding and intention to create a legal obligation.

While written format, formal signatures, and notarization can be important in certain contexts or types of contracts, they are not essential for every contract to be considered legally binding. Many valid contracts can exist orally or in informal formats, provided there is evidence of mutual assent. In some cases, agreements may be considered enforceable without any signatures or notarization as long as the terms are clear and the intent to create a binding agreement is evident between the parties involved.