Thai Names and Nicknames: Khun, Phi, Nong and How to Address People

Published 19 October 2026 · By the Visit-Thailand editorial team · Editor: Terje Moy

Thais are addressed by their first name, not their surname, usually with the polite word Khun in front: Somchai Wangdee is "Khun Somchai". Among friends and colleagues almost everyone goes by a short nickname given at birth, and the words Phi (older) and Nong (younger) are added to show who is senior.

For a visitor this is easier than it sounds. "Khun" plus a first name or nickname is polite in almost every situation, and nobody expects a foreigner to get the finer points right. This page explains the system behind it: the three names a Thai person has, the small words that go in front of them, why surnames are so long, and how your own name will look on Thai paperwork.

First names, not surnames

The most common mistake foreigners make is to use the family name. Thailand Foundation, the cultural body set up under the Ministry of Foreign Affairs, gives the standard example: a man named Somchai Wangdee is "Mr. Somchai", never "Mr. Wangdee". The same applies in a bank, at a hospital, in an office email and on a name badge. A manager is still Khun plus first name.

Surnames do matter on paper. They appear on ID cards, contracts and house registrations, and two Thais who share a surname are, as a rule, related. In everyday speech, though, you can go years knowing a Thai colleague without hearing their surname at all.

Nicknames: the name you will actually hear

Almost every Thai has a chue len, a "play name". Parents choose it at birth, often before the official name is registered, and it stays for life. It is usually one syllable and has nothing to do with the first name: a woman called Thanyamas may be known to everyone as Nu, which means "mouse". Thailand Foundation lists the usual sources as a baby's looks, qualities the parents hope for, birth order, favorite foods or objects, animals, plants and foreign words.

English words are now very common. Surveys quoted by the foundation found nicknames such as Ice, Boss, Beam, Win, Mint, Fern and Cream among the most popular for children born in the late 2000s. Older nicknames are often Thai words for colors or animals, such as Daeng (red) or Kai (chicken). Some traditions are older still. According to custom, a baby might be given an unflattering name such as Moo (pig) so that bad spirits would leave the child alone, and some Thais still avoid praising a baby as beautiful for the same reason.

A nickname is not only for close friends. Colleagues, shop staff you see every week and your landlord may all introduce themselves with one. If someone tells you their nickname, use it, with Khun or Phi in front if you want to be polite.

Khun: the safe default

Khun (คุณ) is the all-purpose polite title. It works for men and women, married or not, and it goes in front of a first name or a nickname: Khun Somchai, Khun Nok. It also means "you" in polite speech, which is why our list of essential Thai phrases uses it in questions such as "what is your name?".

Thais will usually call you Khun plus your first name, so a guest called David Smith becomes "Khun David" at hotel reception. Do not use Khun about yourself; it is a word of respect for others. Combine it with the polite endings khrap (for men) or kha (for women) and with a wai, the Thai greeting with joined hands, and you have covered most of Thai courtesy.

Phi and Nong: older and younger

Phi (พี่) means older brother or sister, and Nong (น้อง) means younger. Thais use these family words far beyond the family. Teaching material from Northern Illinois University's Southeast Asia program explains that kin terms replace pronouns at home and are used outside it "to display courtesy and to reduce social distance". A slightly older colleague becomes Phi Nok; a younger one is Nong Beam.

In practice you will hear:

• Phi for an older friend, a senior colleague, or a stranger you want to address politely and who looks older than you.
• Nong for someone clearly younger. Customers often call young restaurant staff "nong" to get their attention, without a name.
• Other family words for older people: Pa (aunt) for a woman about your mother's age and Yai for someone of your grandmother's age, according to the same NIU material. Lung (uncle) is the everyday word for an older man, such as a motorbike-taxi driver.

For a visitor, the rule is simple: Khun is never wrong. Phi and Nong sound warmer, but they depend on guessing someone's age, so let the Thai person lead. If a colleague starts calling you Phi, they are telling you they see you as the senior.

Teachers, professionals and the titles on forms

Some jobs come with their own title that replaces Khun. A university lecturer, a meditation teacher or a respected expert is Ajarn (อาจารย์), often written "Ajarn" or "Achan" in English, and the title is used with the first name. A schoolteacher is Khru. Doctors are often addressed as Mor (doctor). Monks have a separate vocabulary altogether; our page on monks in Thai daily life explains their place in society, and a respectful wai is all a visitor needs.

On official forms you will meet three other words: Nai (Mr.), Nang (Mrs.) and Nangsao (Miss). They appear before the full name on ID cards, bank documents and contracts, but nobody uses them in conversation.

Why Thai surnames are so long

Surnames are a recent idea in Thailand. They became compulsory in 1913, and because few families had one, most simply chose a new name with a good meaning. The rule from the start was that a family name had to be unique: if a name was already registered, the next family had to change or extend it. That is why Thai surnames often run to five or more syllables.

The current Personal Name Act of 1962 (B.E. 2505) keeps that rule. Section 8 says a new surname must not duplicate one already registered, must not be offensive, and may have no more than ten consonants, with some exceptions. Many of the longest names belong to Thai-Chinese families. According to Thailand Foundation, Chinese families at first registered their clan name with the Thai word "sae" in front, and later chose longer Thai surnames that often keep the meaning of the Chinese name inside them.

The "B.E." in a law's name is the Buddhist Era year; our guide to Thai dates and the Buddhist Era explains how to convert it.

Married names: a free choice since 2005

Older guides, and even some current ones, say a Thai woman takes her husband's surname. That has not been the rule since the Personal Name Act (No. 3) of 2005 (B.E. 2548). Spouses now agree between themselves: either one may use the other's surname, or each keeps their own, and they can decide at the wedding or later. After a divorce, a spouse using the other's surname goes back to their own.

Mixed couples usually meet this at the district office. The legal steps of marrying, from the embassy affirmation to the registration, are in our guide to marrying a Thai citizen, and the ceremony itself is covered from the guest's side in our page on Thai weddings.

Spelling Thai names in English

There is no single English spelling of a Thai name. Thailand has an official romanization system, the Royal Thai General System of Transcription (RTGS), but people choose their own spelling for passports and business cards, and many prefer forms that follow the Thai letters rather than the sound. The same name can appear as Somchai, Somchay or Somchaai, and a surname can look quite different on two documents.

For practical purposes, always copy a Thai name exactly as it appears on the person's own card or passport, especially on bookings and money transfers. The same variety affects street and district names, which is one reason our explainer on how Thai addresses work recommends keeping the Thai script alongside the English.

Your own name in Thai

Foreign names are written in Thai script by sound, so the Thai spelling of your name depends on whoever writes it first. On an employment contract, a lease or a house registration book, it is sensible to ask for the same Thai spelling every time, so that your documents match. Keep a photo of the first official version and show it to the next office.

In daily life you will simply be Khun plus your first name. Long or hard-to-say names often get shortened, and many foreigners living in Thailand end up with a Thai nickname given by colleagues. Take it as friendliness. If you are learning the language seriously, our page on studying Thai on an education visa covers schools and the visa side, and our article on what "farang" means explains the word you may hear used about foreigners in general.

Frequently asked questions

Should I call a Thai person by their first name or surname?

By the first name, with Khun in front: Khun Somchai, not Mr. Wangdee. This applies at work and in formal settings too. If the person gives you a nickname, you can use Khun plus the nickname instead.

What does Phi mean before a Thai name?

Phi means older brother or sister, and Thais use it for anyone a little older than themselves, such as a senior colleague or older friend. Nong is the opposite, for someone younger. As a visitor you can always use Khun instead.

Why do Thai people have nicknames?

Parents give a short nickname at birth, often before the official name is registered, and it is used for life by family, friends and colleagues. Official Thai first names tend to be long, so the nickname is simply easier in daily life.

Do Thai women take their husband's surname?

Not automatically. Since the Personal Name Act (No. 3) of 2005, spouses agree whether one takes the other's surname or both keep their own. Many women still choose the husband's name, but it is a choice, not a rule.

Sources

• Thailand Foundation – The captivating stories behind Thai names (checked October 2026)
• Northern Illinois University SEAsite – Thai kinship terms: explanation (checked October 2026)
• Wikisource (Royal Gazette text) – Personal Name Act B.E. 2505 (1962), in Thai (checked October 2026)
• Wikisource (Royal Gazette text) – Personal Name Act (No. 3) B.E. 2548 (2005), in Thai (checked October 2026)