Mục lục bài viết
1. Contracts Violating Legal Prohibitions or Contrary to Social Morality
A contract with a purpose or content that violates legal prohibitions or is contrary to social morality is deemed invalid. Legal prohibitions are provisions of the law that prohibit individuals from engaging in certain acts. Social morality refers to common standards of conduct in social life that are recognized and respected by the community.
The statute of limitations for requesting a court to declare a contract invalid in this case is not restricted.
2. Sham Contracts
A sham civil transaction is understood as a contract established fictitiously to conceal another contract. Such a sham contract is declared invalid, while the concealed contract remains valid unless it is also invalid under the provisions of the Civil Code or other relevant laws.
Note: A contract established fictitiously to evade obligations toward a third party is also declared invalid.
Thus, there are two cases where a contract is considered sham: when it is established to conceal another contract or to evade obligations toward a third party.
The statute of limitations for requesting a court to resolve such cases is not restricted.
3. Contracts Entered into by Minors, Persons Lacking Civil Act Capacity, Persons with Difficulties in Cognition or Behavior Control, or Persons with Restricted Civil Act Capacity
A contract is invalid in this case due to a violation regarding the legal capacity of the contracting parties, specifically those listed above who lack full civil act capacity appropriate to the contract.
When a contract is entered into by a minor, a person lacking civil act capacity, a person with difficulties in cognition or behavior control, or a person with restricted civil act capacity, the court, at the request of their representative, may declare the contract invalid if the law requires such a contract to be entered into, performed, or agreed upon by their representative, except in the following cases:
- Contracts entered into by persons under 6 years old or persons lacking civil act capacity to meet their essential daily needs;
- Contracts that only generate rights or exempt obligations for minors, persons lacking civil act capacity, persons with difficulties in cognition or behavior control, or persons with restricted civil act capacity toward the counterparty;
- Civil transactions acknowledged as valid by the person who entered into them after reaching adulthood or regaining full civil act capacity.
The statute of limitations for requesting a court to declare a contract invalid in this case is 2 years from the date the representative of the minor, person lacking civil act capacity, person with difficulties in cognition or behavior control, or person with restricted civil act capacity knew or should have known that the represented person independently entered into or performed the contract.
4. Contracts Entered into Due to Mistake
A contract entered into due to a mistake is one where the mistake causes one or both parties to fail to achieve the intended purpose of entering into the contract.
Upon discovering a mistake, the mistaken party may request the court to declare the contract invalid, except in cases where:
- The purpose of entering into the contract has been achieved; or
- The parties can immediately rectify the mistake to achieve the contract’s intended purpose.
The statute of limitations for requesting a court to resolve such cases is 2 years from the date the mistaken party knew or should have known that the contract was entered into due to a mistake.

Cases of Invalid Civil Contracts under Vietnamese Law
5. Contracts Entered into Due to Deception, Threat, or Coercion
When a party enters into a contract due to deception, threat, or coercion, they may request the court to declare the contract invalid.
Deception in a contract refers to an intentional act by one party or a third party to mislead the other party about the subject, nature, or content of the civil transaction, leading to the establishment of the contract.
Threat or coercion in a contract refers to an intentional act by one party or a third party to force the other party to enter into the contract to avoid harm to their life, health, honor, reputation, dignity, property, or that of their close relatives.
This case of invalidity arises due to a violation of the requirement that contracting parties must act voluntarily.
The statute of limitations for requesting a court to resolve such cases is 2 years from the date the threatening or coercive act ceases.
6. Contracts Entered into by Persons Unable to Recognize or Control Their Actions
A person with civil act capacity who enters into a contract at a moment when they are unable to recognize or control their actions may request the court to declare the contract invalid.
When requesting the court to declare such a contract invalid, the requesting party must provide evidence proving that the contract was entered into at the exact moment they were unable to recognize or control their actions.
The statute of limitations for requesting a court to resolve such cases is 2 years from the date the person unable to recognize or control their actions entered into the contract.
7. Contracts Failing to Comply with Form Requirements
A contract that violates the legal requirements regarding form is invalid, except in the following cases:
- A contract required to be in writing but does not comply with legal form requirements, where one or both parties have performed at least two-thirds of the contract’s obligations, may be recognized as valid by the court at the request of one or both parties.
- A contract established in writing but violating mandatory notarization or authentication requirements, where one or both parties have performed at least two-thirds of the contract’s obligations, may be recognized as valid by the court at the request of one or both parties. In this case, the parties are not required to perform notarization or authentication.
The statute of limitations for requesting a court to declare a contract invalid due to non-compliance with form requirements is 2 years from the date the contract was entered into.
8. Legal Consequences of Invalid Principal and Ancillary Contracts
- The invalidity of a principal contract terminates the ancillary contract, unless the parties agree that the ancillary contract replaces the principal contract. This provision does not apply to measures securing the performance of obligations.
- The invalidity of an ancillary contract does not terminate the principal contract, unless the parties agree that the ancillary contract is an inseparable part of the principal contract.
Disclaimer:
This article is intended for informational purposes only and does not constitute legal advice from HTH & Partners. The content represents the views of HTH & Partners and is subject to change without prior notice.
The legal provisions referenced in this article were valid at the time of publication but may have been amended or repealed by the time of reading. We strongly recommend consulting a qualified legal professional before applying any information contained herein.