Capacity

A person, on completion of twenty years of age ceases to be a minor and becomes a person who is capable of managing one's own affairs and who has all the rights and is not under the power of another.

Legal Capacity in Thailand

Legal capacity in Thailand refers to a person's legal ability to manage their own affairs, exercise rights independently and enter into binding legal acts. The general rules are contained in the Thai Civil and Commercial Code and are particularly relevant to contracts, property transactions, marriage, powers of attorney and other juristic acts.

Updated August 2026: expanded information on age of consent and the protection of minors under Thai law.

Age of Majority in Thailand

Under Section 19 of the Thai Civil and Commercial Code, a person ceases to be a minor upon reaching the age of twenty years and becomes sui juris.

The general age of majority in Thailand is therefore 20 years. From that age, a person normally has full civil legal capacity to manage his or her own affairs and enter into legal transactions independently.

The age of majority should not be confused with other legal age limits. Thai law uses different age thresholds for matters such as marriage, testamentary capacity and criminal responsibility.

Legal Capacity of Minors

A person under twenty years of age is generally a minor under Thai civil law and does not automatically have full capacity to carry out every juristic act independently.

Under Section 21 of the Civil and Commercial Code, a minor generally requires the consent of his or her legal representative before entering into a juristic act, unless otherwise provided by law.

The Code contains a number of exceptions. For example, a minor may independently perform acts which are purely beneficial to the minor or which concern rights that are strictly personal. Other provisions permit certain transactions appropriate to the minor's circumstances.

Where consent is legally required but has not been obtained, the act is generally voidable rather than automatically void. The effect therefore depends on the type of transaction and the applicable provisions of the Civil and Commercial Code.

Marriage and Legal Capacity

Marriage creates an important exception to the general rule that full civil capacity begins at twenty.

Under Section 20 of the Civil and Commercial Code, a minor becomes sui juris upon a valid marriage made in accordance with Section 1448.

Following the amendments introduced by Thailand's Marriage Equality Act, the normal minimum age for marriage under Section 1448 is now 18 years, increased from the previous age of 17. In appropriate circumstances, the court may permit marriage below that age.

This creates an important distinction. An unmarried person aged 18 or 19 is still generally a minor for civil-law purposes, while a person of the same age who has validly married may already be sui juris under Section 20.

Capacity to Enter Into Contracts

Legal capacity is particularly important when entering into contracts and other juristic acts.

Where a contracting party is under twenty, it may therefore be necessary to determine whether that person is still legally a minor, has become sui juris through marriage, or requires the consent of a legal representative.

This can be relevant to transactions such as:

• sale and purchase agreements;
• leases and tenancy agreements;
• loan agreements;
• gifts and transfers of property;
• property-related agreements; and
• other contracts creating legal or financial obligations.

A person's age alone therefore does not always provide the complete answer to whether he or she can independently enter into a particular transaction.

Civil Legal Capacity and Criminal Responsibility Are Different

The age rules governing civil legal capacity should also not be confused with the separate rules governing criminal responsibility under the Thai Penal Code.

For civil-law purposes, the general age of majority is 20 under Section 19 of the Civil and Commercial Code. The Penal Code uses different age thresholds when determining the criminal responsibility of children and young persons.

For example, Section 73 of the Penal Code provides a specific rule for a child not over twelve years of age, while Section 74 deals separately with a child over twelve but not over fifteen years of age.

These criminal-law age rules do not determine whether a person can independently enter into a contract, transfer property, marry or carry out another juristic act under the Civil and Commercial Code.

For the criminal-law provisions, see the full Thai Penal Code English translation.

Age of Consent and Legal Capacity Are Not the Same

The age of consent in Thailand is another example of a separate legal age threshold. It does not determine whether a person has full civil capacity to enter into contracts, transfer property or manage financial affairs.

Section 277 of the Thai Penal Code makes sexual intercourse with a child not yet over fifteen an offence regardless of the child’s apparent consent. However, this commonly quoted age should not be understood as a general safe age for every form of sexual conduct. Other provisions protect persons under eighteen against exploitation, prostitution, trafficking, sexual images and removal from parental care for an indecent purpose.

A person who has reached fifteen therefore does not become an adult or acquire full legal capacity. The general age of civil majority remains twenty, while separate criminal and child-protection provisions use their own age limits for particular purposes.

For more detailed information on ' Legal Age of Sexual Consent' read more...

Legal Age to Drive a Car

The minimum age to obtain a Thai driving licence for a private car is 18 years. Under the Motor Vehicle Act B.E. 2522 (1979), an applicant for a temporary private driving licence must be at least 18 and must also meet the statutory health, knowledge and driving-test requirements.

A limited exception applies to motorcycles: a person aged 15 or older may apply for a motorcycle licence for motorcycles with an engine capacity not exceeding 110 cc. This exception does not apply to driving a car. The driving-licence age is separate from civil-law majority. Although a person remains a minor under the Civil and Commercial Code until age 20, he or she may obtain a car driving licence from age 18.

Legal Age to Buy Alcohol

In Thailand, alcoholic beverages may not be sold to a person under 20 years of age. Section 29 of the Alcoholic Beverage Control Act B.E. 2551 (2008) prohibits the sale of alcohol to anyone under 20, as well as to a person who is intoxicated to the point of losing self-control.

The law is framed primarily as a restriction on the seller: it prohibits selling alcohol to a person under 20. It does not create a general rule stating that every act of drinking alcohol by a person under 20 is itself a separate age-based offence. Consumption is, however, separately prohibited in certain places and areas under the Alcoholic Beverage Control Act and related regulations.

Accordingly, 20 is the practical legal age for purchasing alcohol in Thailand.

Legal Age to Make a Will

In Thailand, a person may make a valid will from the age of 15 years. Section 25 of the Civil and Commercial Code expressly allows a minor who has reached 15 to make a will, even though legal majority is normally reached at age 20. A will made by a person under 15 years of age is void under section 1703 of the Civil and Commercial Code.

Incompetent and Quasi-Incompetent Persons

Legal capacity may also be restricted independently of age.

Under the Civil and Commercial Code, a court may in circumstances prescribed by law adjudge a person incompetent or quasi-incompetent. Depending on the court order and the applicable provisions, a guardian or curator may be appointed and the person's ability to carry out legal acts independently may be restricted.

Legal capacity should therefore not always be determined by age alone. A person over twenty may still be subject to legal restrictions on capacity following a court order.

Wills and Powers of Attorney

Different legal acts may also have their own specific capacity requirements.

A Last Will and Testament, for example, is subject to special testamentary-capacity rules. Thai succession law permits a minor who has completed fifteen years of age to make a Will, while a Will made by a person who has not completed the age of fifteen is void.

This is another example of why the general age of majority of twenty should not be treated as the legal age for every possible act.

Capacity is also relevant when granting a power of attorney. A principal cannot generally give an agent greater legal authority to perform an act than the principal is legally capable of granting for that transaction.

For the statutory provisions governing minors and civil legal capacity, see Sections 19 onwards of the Thai Civil and Commercial Code.

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