1. Handwritten agreement has legal effect. A handwritten contract is valid as long as it is the true intention of both parties, the content of which does not violate the law, and both parties who sign the contract have corresponding capacity for civil rights and civil conduct.

2. Legal basis: Article 143 of the Civil Code of People's Republic of China (PRC).

A civil juristic act that meets the following conditions is valid:

(1) The actor has corresponding capacity for civil conduct;

(2) the meaning is true;

(three) does not violate the mandatory provisions of laws and administrative regulations, and does not violate public order and good customs.

Second, can the handwritten contract be revoked?

A handwritten contract is irrevocable. A legally established contract is protected by law and is legally binding on all parties. If one party fails to perform the contractual obligations or fails to meet the contractual obligations, it shall be liable for breach of contract, such as continuing to perform, taking remedial measures or compensating for losses. The amount of compensation for losses is generally not greater than the losses caused by breach of contract, and the losses include the benefits that can be obtained after the performance of the contract. Going back on our word after signing a contract is a breach of contract, and the breaching party has no right to terminate the contract. Therefore, the breaching party not only needs to bear the responsibility of delaying the performance of the contract, but also needs to bear the obligation to continue to perform the contract. The parties may stipulate in the contract the circumstances of breach of contract, the amount of liquidated damages and the calculation method of liquidated damages. If the liquidated damages are lower than the actual losses, the parties may claim compensation according to the actual losses. If the liquidated damages are excessively higher than the actual losses, the parties may request an appropriate reduction. If the liquidated damages exceed 30% of the losses caused, it can be considered as excessively higher than the actual losses. Therefore, it is generally impossible to go back on our word when concluding a contract. If you renege, you need to bear the corresponding liability for breach of contract.