One issue that has been asked many times at the Pattaya office are about the rights of fathers in Thailand with regards to their illegitimate children. The issue is complex and it is best to speak to an attorney in this regards. The question has been asked and it was best answered not to long ago by Justice Krasaesaen as follows:
“If you and your child’s mother were not married when his/her birth was registered, the mother has sole rights as his/her guardian.
Although you are the child's natural father, you have no legal right to take the child out of the country or to change either the child’s given or family name. To do either, you must be the child’s registered guardian. For you to become the guardian of the child, you and the child's mother must go the District Office where the child is registered on the house registration document (tabien baan). The mother must provide written permission and testify in person before you can become his/her guardian.
If she refuses, or if you are unable to contact her, you can apply to the Family Court for permission to be the sole guardian of the child. You will need to take with you your child, your passport, your child's birth certificate and the house registration document on which he/she is registered, as well as a person willing to testify in support of your application. The court may ask for additional evidence to support your case.
The court will allow 60 days for any person to object to your application.
If the court finds you to be a suitable guardian for the child, you can then take the court’s written permission and apply for sole guardianship at the District Office. Once your application is approved, you may then take your son out of the country. You may also change his/her name.”