The signature or seal of the parties to the contract is valid. The law does not stipulate that the contract signature must be combined with the seal to take effect. The legal representative exercises the right to conclude a contract on behalf of the enterprise. If the legal representative of the enterprise signs the contract but does not affix the official seal of the enterprise, the contract is usually valid. However, if both parties clearly stipulate in the contract that the contract will take effect after being signed and sealed, then the contract has not yet taken effect if only the legal representative of the enterprise signs it but does not affix the official seal of the enterprise. In this case, a contract without an official seal is invalid only if it is signed by the legal person.

If the party who should perform the debt first has definite evidence to prove that the other party has one of the following circumstances, it may suspend the performance:

1, the operating conditions have deteriorated seriously;

2. Transfer property, withdraw funds and evade debts;

3. Loss of business reputation;

4. There are other circumstances that have lost or may lose the ability to perform debts.

Creditor's rights and debts shall be terminated under any of the following circumstances:

1, the debt has been fulfilled;

2. The debts offset each other;

3. The debtor shall deposit the subject matter according to law;

4. Creditors are exempted from debts;

5. Creditor's rights and debts belong to one person;

5. Other circumstances under which the termination is stipulated by law or agreed by the parties.

Problems that should be paid attention to when signing labor contracts;

1. When signing a contract, workers must first understand the basic situation of the company and judge whether it is a legitimate enterprise. The name, address and telephone number of its legal representative shall be known. This information can be obtained by searching industrial and commercial registration information on the Internet, and it is required to clearly write these contents in the contract.

2. Laborers should be clear about their specific work, and indicate the content and specific location of the work in the contract.

3, labor remuneration should be clear, avoid verbal agreement. If the standard salary, bonus and bonus are based on what standards, these data must be reflected in the contract, and don't trust the boss's verbal commitment.

4. Pay special attention to the probation period. The law stipulates that the probation period shall not exceed six months at the longest, and the contract that only stipulates the probation period is invalid. It is cheating to ask workers to leave after the probation period. During the probation period, the employer shall not terminate the labor relationship without reason; Employees can leave their jobs unless they do not meet the recruitment requirements.

5. The payment method and time of labor remuneration should be clear, whether it is cash payment or bank payment. Some units bind workers by withholding one month's salary, which has no legal effect. After the termination of the labor contract, if the employer refuses to provide the withheld labor remuneration, the employee may settle it through labor arbitration.

Common situations of invalid labor contracts:

1. Labor contract whose contents violate laws and administrative regulations. The probation period is more than 6 months, and no social insurance is purchased.

2. Labor contracts that are forced to be signed by coercion or taking advantage of others' danger, causing the other party to suffer damage to life, health, honor, reputation and property. Forcibly renewing the labor contract after the expiration of the contract.

3. A contract concluded by one party against its true meaning by fraudulent means and deliberately concealing the facts. For example, a false promise of good working conditions.

4. Conclude a labor contract through illegal procedures. If the two parties fail to negotiate or adopt a special working hour system without approval.

5. Violation of labor safety protection system. For example, it is agreed that the workers themselves are responsible for work-related injuries and occupational diseases, and the legal responsibility of the employer is exempted.

6. Labor contracts that charge various fees in violation of regulations. Such as compulsory collection of training fees, deposits, mortgage payments, venture funds, stock funds, etc.

7, the main unqualified labor contract. For example, recruiting child labor and signing contracts.

8. Labor contracts that infringe on marital rights. If it is stipulated that employees are not allowed to fall in love, get married or have children during the contract period.

9. Labor contracts that violate the right to health. If the agreed working hours exceed the legal provisions, it will damage the normal rest and vacation of workers.

10, labor contract that infringes on the right to remuneration. Overtime is not paid, and wages below the minimum wage are paid.

To sum up, the conclusion of a labor contract should follow the principles of legality, fairness, equality, voluntariness, consensus, honesty and credibility. The labor contract concluded according to law is binding, and the employer and the employee shall perform the obligations stipulated in the labor contract.

Legal basis:

Article 465 of the Civil Code of People's Republic of China (PRC)

Contracts established according to law are protected by law.

A legally established contract is legally binding only on the parties, except as otherwise provided by law.