Thai surnames: why they're long, and how they work

Someone in your family has a surname that takes a full breath to say. Maybe it’s yours. Maybe a teacher abroad paused at it every school year, while your cousins in Thailand never seemed to use theirs at all. Both things make sense once you know how Thai surnames came to be.

How do you say last name in Thai?

Surname, or last name, is นามสกุล (naam sa-gun). On a Thai form it comes after your first name, the same order as in English. You’ll find it in our glossary too.

What’s different is how little the surname is used out loud. More on that below.

When did Thai people get surnames?

Surprisingly recently. Before 1913, most Thais had only a given name. The researcher Supaporn Shigetomi writes that people identified themselves by their parents’ names or the place they lived, and that it was hard to tell people apart because so many shared the same name.

King Vajiravudh (Rama VI), who had studied in Britain, wanted that to change. Shigetomi describes how, soon after he came to the throne, he called for birth, death and marriage registration and decided everyone needed a surname to be identified properly. The first Surname Act followed in 1913. Thailand’s current law, the Person’s Name Act of 1962, lists the Surname Designation Act B.E. 2456 (1913) as one of the earlier laws it replaced.

Some surnames were granted by the King himself, and those are still protected today: the law says a new surname must not repeat “the Surname conferred by the King or the registered Surname”. You’ll see different counts online for how many King Vajiravudh granted. We couldn’t confirm a figure from a source we trust, so we’re leaving the number out.

So a Thai surname is often only three or four generations old. If you ask an elder who chose yours, there’s a fair chance someone remembers.

Why are Thai last names so long?

Two reasons, and they feed each other.

Each family needs its own. Wikipedia’s article on Thai names puts it simply: surnames are required to be unique to a family, and they are usually quite long as a result. There’s no shared stock of common names like Smith or Andersson. Today’s Person’s Name Act says a new surname must not repeat one that is already registered. The person who registered it can let other Thai nationals use it, through the local registrar, and after their death “the most immediate, surviving descendant” who still uses the name can do the same. Every new family had to find a combination nobody had registered yet.

The English spelling can stretch them. Wikipedia notes that some surnames, especially ones bestowed by the king, are romanized from their original Pali or Sanskrit root rather than by the standard Thai system, which is why the English spelling can look nothing like how the name sounds.

The law does put a cap on length: in the Office of the Council of State’s English translation, a surname must “not comprise of more than 10 alphabetical letters, except where the title conferred by the King is used as a Surname”. How that count works in Thai script is a question for the district office, not for us.

What does a Thai surname mean?

It depends entirely on the family. Because each one was made for one family, there’s no shared list of meanings the way there is for English surnames. Some hide an older Chinese name (more on that below). The best source for yours is the family itself, and anyone who reads Thai can help you break it into its parts.

Do Thai people call each other by their last name?

No. In Thailand, people are addressed by their given name, not their surname. Wikipedia sums it up: Thais are not addressed by their family name alone, and in polite speech the given name usually comes with khun in front. The same article notes that directories list people by given name too.

Day to day, most people go one step further and use a nickname, the ชื่อเล่น (chue len) given by their parents. Plenty of people know their colleagues’ nicknames and couldn’t tell you their surnames. Our guide to Thai nicknames has 100 of them, with meanings.

So if your surname gets stumbled over abroad, take heart: in Thailand, almost nobody says it either. If you’re wondering what to call Thai people in the first place, that one’s simple.

Why do some Thai Chinese families have Thai-sounding surnames?

Many families of Chinese origin took Thai surnames, and some kept a trace of the Chinese name inside. Wikipedia gives two well-known examples from politics: the first syllable of Shinawatra comes from a Chinese surname, and the archa in Silpa-archa means “horse”, a Sanskrit rendering of the Chinese surname Ma. Other families kept no trace at all. Our guide to Thai Chinese families explains the history behind that, including the years when Sino-Thai officials were urged to drop their Chinese surnames.

Does a Thai woman take her husband’s surname?

She can, but she doesn’t have to. The rules have swung back and forth:

• 1913: Shigetomi quotes the first Surname Act as saying a married woman could take her husband’s surname or keep her maiden name.
• 1941: a new Person’s Name Act (Shigetomi calls it the Personal Name Act) required wives to use their husband’s surname. Shigetomi notes that women who had kept their maiden names were not allowed to register a divorce until they changed it.
• 1962: divorced women could go back to their maiden surname, and widows could choose.
• 2005: today’s rule came with the Person’s Name Act (No. 3), B.E. 2548 (2005). Section 12, in the Office of the Council of State’s translation: “The spouse has the right to use the Surname of either party as agreed or each party is entitled to use his or her previous Surname.” The agreement “can be made upon marriage or during marriage” and “can be subsequently amended by the spouse”. After a divorce or annulment, whoever uses the other’s surname “shall return to using his or her previous Surname”. A widow or widower may keep the other’s surname, but returns to their own on remarrying. A 2010 study in the Naresuan University Law Journal also dates the change to 2005: before it, married women had to take their husband’s surname.

A note on dates: Shigetomi’s 2014 paper says the law “was revised and enforced in 2002”. The Office of the Council of State’s translation, which lists every amendment, dates the change to Act No. 3 of B.E. 2548 (2005), and we follow that. We couldn’t confirm what, if anything, happened in 2002.

That translation is unofficial: its own disclaimer says only the Thai text has legal force. If a surname change matters for your papers, confirm with your embassy or the district office before you rely on this page.

So if your mum has a different surname from your dad on her Thai ID, that’s normal. If she changed hers when she married, that’s normal too.

Which surname goes on a Thai child’s papers if they’re born abroad?

This is where it gets practical, and where the details depend on your embassy. Here’s what the two embassy pages we checked say:

• Stockholm: “a child must use either the father’s or the mother’s surname”, not both together, and the surname should match in the Thai and Swedish records.
• Washington DC: the first and last name must match the US birth certificate exactly and comply with Thai law, and the last name must be the legal last name of the father or the mother.

Washington DC also asks that the spelling match the parent’s official Thai documents. So a double-barrelled surname on a local birth certificate may not carry over as it is. If the parents aren’t married and the child will use the father’s surname, Stockholm asks for extra forms, including an application for registration of surname use. Rules differ by country and change, so confirm with your embassy before you file anything.

Our guide to registering a birth at a Thai embassy compares several embassies side by side. And if the Thai birth certificate is a step toward a passport, see should I get my Thai passport?

The short version

Your Thai surname is little more than a century old at most, made for your family alone. It’s often long because it had to be unique. And in Thailand it mostly lives on paper, while the people who love you call you by your nickname.

Thai words on this page are a draft until a native speaker has reviewed them.