Which of the following is NOT one of the four elements of a valid contract?

A valid contract typically requires four essential elements, which are: competent parties, mutual agreement (which encompasses both an offer and acceptance), consideration, and lawful purpose.

In this context, the element of written documentation does not constitute a necessary requirement for a contract to be valid. While many contracts are in written form for the sake of clarity and to provide evidence of terms, not all contracts need to be written to be legally enforceable. Many express contracts are verbal, provided they involve competencies defined by law and adhere to any specific requirements of statutory law, such as the Statute of Frauds, which requires certain types of contracts to be in writing.

Therefore, the assertion that written documentation is not one of the four essential elements of a valid contract is accurate.