Whether it is valid for a husband to sign a contract on behalf of his wife is as follows: The legal effect of a husband signing a contract on behalf of his wife depends on the actual situation. If the wife entrusts her husband to sign the contract or the wife admits that her husband signed the contract, the contract is valid. Pay attention to entrusting others to sign the contract: 1. The agent shall handle the entrusted affairs according to the instructions and requirements of the principal. Only when the trustee engages in entrusted activities according to the instructions and requirements of the principal can he admit the consequences of the trustee's handling of entrusted affairs; 2. The entrustment contract has strict personal attributes. The conclusion and performance of the entrustment contract is based on the mutual trust between the principal and the trustee, which has strict personal attributes. The law requires that the trustee must personally handle the entrusted affairs; 3. The object of entrustment contract is the agent's behavior in handling entrusted affairs. The entrustment contract is the object of the trustee to handle the entrusted affairs, because the purpose of the entrustment contract between the principal and the trustee is to realize the result pursued by the principal through the trustee to handle some entrusted affairs.