Révisé par ThaiLawOnline, un cabinet d'avocats thaïlandais agréé exerçant en Thaïlande depuis 2006. Avocate thaïlandaise en charge du dossier : Wichuda Atthamethakon, LL.M., licence du barreau thaïlandais 3149/2556.
Dernière mise à jour le 24 août 2026
Réponse courte : if you were not married to the mother, you are not the child’s legal father in Thailand, whatever the birth certificate says. Under section 1546 of the Civil and Commercial Code the child is the legitimate child of the mother alone, and section 1547 gives exactly three ways to change that: marry the mother, register the legitimation, or obtain a court judgment. Nothing else works, and time does not do it for you.
The trap: registration needs the mother’s consent, and under section 1548 silence counts as refusal, not agreement. If she neither objects nor consents within 60 days of being notified, she is presumed pas to consent and the registration fails. Waiting achieves nothing. See the three routes.
Table des matières
The Three Routes to Becoming the Legal Father
| Itinéraire | What it requires | Suits you when |
|---|---|---|
| 1. Marry the mother | A registered marriage after the birth. Legitimation follows automatically. | You are together and marrying anyway. Simplest route by a distance. |
| 2. Register the legitimation at the amphur | The consent of both the child and the mother, given before the registrar. | Relations are good and she will attend. Cheap and quick when it works. |
| 3. Court judgment | An action for the child to be declared yours. Does not depend on her agreement. | She refuses, cannot consent, is unreachable, or simply does not respond. This is the route most contested cases end on. |
Legitimation takes effect from the date of the child’s birth, not from the date of registration or judgment, although it cannot be used to prejudice third parties who acted in good faith in the meantime. So the delay costs you time, not the child’s status.
The Consent Sequence, and Why Waiting Fails
This is the part that catches foreign fathers, because it runs opposite to the intuition that silence means acquiescence.
| Scène | What section 1548 provides |
|---|---|
| You apply | The father may register the child as legitimate only with the consent of the child and the mother. |
| They do not attend | The registrar notifies the child and the mother of your application. |
| 60 days pass with no answer | They are presumed NOT to consent. The registration does not go through. If the child or mother is outside Thailand the period is 180 jours. |
| She objects, refuses, or cannot consent | Inscription doit be effected by a judgment of the court. |
| You obtain the judgment | Produce it to the registrar and the registration is made. |
Read that third row again. A father who files at the amphur and waits, expecting silence to carry the day, is simply out 60 days and no further forward. Where you have any reason to think consent will not come, the court route is not the fallback, it is the plan.
Registration Does Not Automatically Give You Parental Power
Even a successful registration can be hollowed out, and this is separately provided for in section 1549.
Au sein de 90 jours of being notified of your application, and whether or not they object to the legitimation itself, the child or the mother may notify the registrar to record that you are not a suitable person to exercise parental power, in part or in whole. If they do, then even though the legitimation is registered, you cannot exercise the parental power covered by that notice until a court rules that you may, or until 90 days have run from the notification.
So there are two distinct fights available to the other side, on two different clocks:
| Article 1548 | Article 1549 | |
|---|---|---|
| What it controls | Whether you become the legal father at all | Whether you can exercise parental power once you are |
| Clock | 60 days from notification, 180 if abroad | 90 days from notification |
| Effect of silence | Presumed refusal, registration blocked | No objection recorded, parental power unaffected |
| How it is resolved | Court judgment on legitimation | Court ruling that you may exercise parental power |
The practical lesson is that “getting my name on it” is not the finish line. A father who wins legitimation and stops there can still find he has no lawful say in schooling, medical decisions or travel.
What Legitimation Actually Gives You, and What It Does Not
| You gain | You do not automatically gain |
|---|---|
| Legal fatherhood, retroactive to the birth | Custody. Parental power is decided separately, and section 1549 can block it |
| Standing to apply to the court about the child at all | Sole custody, which remains a separate application on the child’s best interests |
| The child’s inheritance rights from you, and yours from the child | A right to remove the child from Thailand without the mother’s agreement |
| The maintenance duty under section 1564, which cuts both ways | Any change to the child’s nationality or passport by itself |
That last row in the left column matters. Legitimation is what makes you liable to maintain the child, so it is not a costless step, and the money question is set out in our guide to child support in Thailand. The custody question is in garde d'enfants en Thaïlande.
Being on the Birth Certificate Is Not Legitimation
The single most common misunderstanding we see. A Thai birth certificate recording your name is evidence about a fact. It is not a legal status, and it does not make you the child’s legal father under section 1547. Fathers discover this at the worst possible moment: at a hospital, at a school, at an immigration counter, or after the mother has died.
If your name is on the certificate and you have never registered legitimation or obtained a judgment, you are in the third row of the first table on this page, not the second.
Legitimation Runs From the Child’s Birth, Not From the Registration
This is the point on which most English-language guidance about Thailand is still wrong, and it is worth more to a father than everything else on this page. Article 1557 provides that legitimacy under section 1547 takes effect from the day of the child’s birth. It is not effective from the date you sign at the district office, and not from the date of the judgment.
The section used to say the opposite. Until 2008 it fixed three separate dates, keyed to the marriage, the registration or the final judgment. It was rewritten by the Civil and Commercial Code Amendment Act (No. 19) B.E. 2551, published in the Royal Gazette volume 125 part 45 Kor on 7 March 2551 and in force on 8 March 2008. Competitor pages that still set out the old three-date rule are quoting text that stopped being law more than fifteen years ago.
One limit travels with the rule, and it is in the same section: retroactivity cannot be set up to prejudice a third person who acted in good faith between the birth and the marriage, the registration or the final judgment. It works against the father and the family; it does not unwind a stranger’s honest transaction.
What Retroactivity Costs: Dika 7345/2560
Because status dates back to birth, so does the maintenance duty in article 1564. A child can claim for the years already gone, in the same action that asks the court to declare paternity. Supreme Court Decision 7345/2560 shows the size of that exposure. A child of unmarried parents claimed 10,000 baht a month from birth to the filing date, 1,720,000 baht in total. The Court of First Instance awarded 1,370,000 baht.
The Court of Appeal Region 1 then halved the award to 685,000 baht, reasoning that both parents are jointly liable and must therefore contribute in equal shares. The Supreme Court restored the full 1,370,000 baht. Joint liability under section 1564 does not mean identical contributions: section 1598/38 requires the court to weigh the ability of the parent who must pay, the station of the child who receives, and the circumstances of the case. Arithmetic is not the method.
Two procedural points from the same judgment are worth knowing. The Supreme Court fixed the amount although the child had not appealed on it, because the level of maintenance is a question of public order, and said expressly that doing so is not deciding beyond what was asked. And the father lost his limitation defence for a reason that catches litigants regularly: he pleaded the five-year prescription for periodical payments at first instance, lost, and tried to substitute a different provision on appeal. The appeal court refused to hear it because it had not been raised below, and prescription being a matter of public order did not save a point that was never pleaded.
The Deadlines Nobody Tells You About
Cancelling a registration: three months, with a ten-year ceiling. Article 1554 lets any interested person apply to cancel a registered legitimation on the ground that the registered man is not the father, but only within three months of learning of the registration, and in no case after ten years from the date of registration.
Suing for legitimation: the clock depends on the child’s age. Sous section 1556, while the child is under fifteen the action is brought by the legal representative, and if there is none, or that person cannot act, a close relative or the public prosecutor may ask the court to appoint a representative for the case. From fifteen the child brings the action personally and does not need consent. After the child becomes sui juris, which is twenty sous section 19, the action must be entered within one year. Miss that year and the route closes.
If the father has died, section 1558 allows the action to be brought within the prescription period for claiming the inheritance, and a child adjudged legitimate takes as a statutory heir; where the estate has already been divided, the Code’s rules on undue enrichment apply.
The Seven Grounds for a Court Action
The judgment route is not open at large. Article 1555 allows an action for legitimation seulement in seven situations: rape, abduction or unlawful confinement of the mother during the conception period; elopement or seduction of the mother in that period; a document from the father acknowledging the child as his; an entry in the birth register naming the man who notified the birth, or notification made with his knowledge; open cohabitation of the father and mother during the conception period; sexual intercourse with the mother during the conception period where there is ground to believe the child is not another man’s; and continuous common repute of being a legitimate child, shown by facts such as the man paying for the child’s education or maintenance or letting the child use his family name. If the man is shown to be incapable of being the father, the case is dismissed.
Foreign Fathers: Which Country’s Law Applies
Nationality is not a bar to any of the three routes, but which law governs the question is set by the Act on Conflict of Laws B.E. 2481, and the section usually quoted is the wrong one. Article 29 governs whether a child est legitimate by birth: that follows the national law of the mother’s husband at the time of the birth, or his national law at his death if he had already died. Section 31 is the provision that governs legitimation by the father’s own act, and it applies the national law of the father at the time of the recognition, or his national law at death if he has died by then. Article 30 then sends the rights and duties between parent and legitimate child to the father’s national law, and where the child was born to a woman not married to a man, the rights and duties between mother and child to the mother’s national law.
The practical consequence is that a foreign father should expect the district office and the court to look at his own national law on legitimation as well as the Thai sections above, and should have that law evidenced. The procedural differences are the ordinary ones: certified translation and legalisation of foreign documents, and the consent window in section 1548 running to 180 days instead of 60 where the child or mother is outside Thailand.
Legitimation is the gateway to every other parental right described in our guide to droit de la famille thaïlandais.
Questions fréquentes sur la légitimation des droits paternels en Thaïlande :
Suis-je le père légal en Thaïlande si je suis sur l'acte de naissance ?
No. Under section 1546 of the Civil and Commercial Code a child born to an unmarried woman is the legitimate child of the mother alone. A birth certificate recording your name is evidence about a fact, not a legal status. Article 1547 gives three ways to become the legal father: marrying the mother, registering the legitimation, or obtaining a court judgment.
Comment un père non marié légitime-t-il un enfant en Thaïlande ?
By one of three routes under section 1547: marrying the mother after the birth, registering the legitimation at the district office with the consent of both the child and the mother, or obtaining a court judgment that the child is his. The judgment route does not require the mother’s agreement.
Que se passe-t-il si la mère ignore ma demande de légitimation ?
Silence defeats the application. Under section 1548, if the child or mother neither objects nor consents within 60 days of being notified, they are presumed NOT to consent, and the period extends to 180 days if they are outside Thailand. Where consent is refused, cannot be given, or never comes, registration must be effected by a court judgment.
Est-ce que l'enregistrement de la légitimation me donne la garde en Thaïlande ?
Not automatically. Under section 1549 the child or mother may, within 90 days of being notified, have the registrar record that you are unsuitable to exercise parental power in part or in whole. If they do, then even after the legitimation is registered you cannot exercise that parental power until a court rules that you may, or until 90 days have run from the notification.
Un père étranger peut-il légitimer un enfant en Thaïlande ?
Yes. Nationality is not a bar to any of the three routes in section 1547. Which country’s law governs the recognition is set by the Act on Conflict of Laws B.E. 2481, whose section 31 applies the national law of the father at the time of the recognition. The other differences are evidential and procedural: documents from abroad need certified translation and legalisation, and where the child or mother is outside Thailand the consent period under section 1548 extends from 60 to 180 days.
La légitimation prend-elle effet à compter de la date de l'enregistrement ou de la naissance ?
From the date of the child’s birth. Article 1557 makes the effect retroactive to birth, as it has since the Amendment Act (No. 19) B.E. 2551 came into force on 8 March 2008. It cannot be relied on to prejudice third parties who acted in good faith between the birth and the marriage, registration or final judgment.
Does legitimation make me liable for child support?
Yes, and back to the child’s birth. The maintenance duty in article 1564 attaches to a legal parent, so legitimation is what creates it, and because status dates back to birth the claim can cover the years already gone. In Decision 7345/2560 the Supreme Court upheld 1,370,000 baht of back maintenance. Parents must maintain and properly educate a child throughout minority, and must continue to maintain an adult child who is infirm and unable to earn a living.
What if the mother has died or cannot be found?
Registration under section 1548 depends on consent that cannot be given in either situation, so the section directs the matter to the court: where the child or mother does not consent or is unable to consent, registration must be effected by a judgment. That is the route, and it is worth starting early because the evidence of the relationship gets harder to assemble over time.
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