Which of the following is NOT required in a home improvement contract?

In a home improvement contract, specific elements are essential to ensure clarity and protection for both the contractor and the homeowner. Among these, the contractor’s license number is crucial as it verifies that the contractor is legally authorized to perform the work. A detailed description of the work is necessary to outline exactly what tasks will be performed, thus avoiding misunderstandings. The total cost of the project is also important, as it provides transparency regarding the financial obligations of the homeowner.

However, proof of the contractor's experience is not a mandatory component of a home improvement contract. While it is beneficial for homeowners to consider a contractor's experience, it does not need to be formally documented in the contract itself. Therefore, including proof of experience is not required for the contract to be valid, making this the correct choice in this context.