Thailand phone numbers: format, mobile prefixes, validation and messaging rules

Thai numbers use the country code +66. Mobile numbers have 9 digits after the code and start with 6, 8 or 9, so they are ten digits at home (08X XXX XXXX) and +66 8X XXX XXXX in E.164. Write the international form with a plus, not as 0066: Thailand uses several exit codes (001, 006, 009 and others), so a parser set to Thailand reads "006" as one and rejects the number. Porting has run since December 2010, and SIM cards are tied to a verified identity.

This guide is part of our phone numbers by country series. The tables are generated from libphonenumber's metadata, our MNP atlas and our public catalog. Example numbers are masked with X. We read the regulator notices, legal texts and press reports cited below between 2026-10-16 and 2026-10-18. Several Thai rules are published only in Thai; for those we relied on official translations, law-firm summaries or press reports and say so. This is a summary, not legal advice.

#What does a Thai phone number look like?

A mobile number is 08X XXX XXXX at home: the trunk prefix 0, a two-digit prefix starting 6, 8 or 9, and seven subscriber digits. From abroad it is +66 8X XXX XXXX. Landlines are one digit shorter: 8 digits after +66, where the first one or two digits are the area code.

The fixed-line example in the table is the first number libphonenumber's pattern accepts, not a typical landline. Real landlines look like this:

Area names come from libphonenumber's geocoding data. The area code is part of the number and is always dialled, even for a call within the same province.

#Why do Thai numbers written as 0066… fail validation?

Because Thailand has several international exit codes, not one. The metadata defines the exit code as 00 followed by any digit from 1 to 9, and operators really do use several of them: the carrier selection codes include 001, 003, 004, 005, 006 and 009, each tied to an international carrier (Telephone numbers in Thailand, citing the NBTC numbering database). 006 is one of them. A parser that is told the number comes from Thailand therefore reads 0066 81 XXX XXXX as exit code 006, then country code 68…, and the result is not a Thai number at all. We confirmed this with both libphonenumber ports we test (row 3 of the test table below).

The fix is one line: rewrite a leading 0066 to +66 before parsing. Inputs that use a real Thai exit code, such as 001 66 81 XXX XXXX, already parse correctly. And as everywhere, store only the E.164 form, +6681XXXXXXX, with no spaces and no 0 after the country code.

#Which prefixes are mobile numbers?

Mobile numbers start 06, 08 or 09. For each 2-digit block, the generator counted every 9-digit number that libphonenumber's mobile pattern for TH accepts:

Three details matter:

• 080–089 and 090–099 are fully mobile. The 09 range was opened after 08 filled up.
• 06 is mixed. 061–066 are mobile, 067 is only partly allocated, and 060 and 068 are VoIP ranges, typed VOIP in the metadata (row 10 of the test table). A VoIP number has the same shape as a mobile, so a regex can't tell them apart.
• 014 is an oddity. The metadata treats it as a mobile block, but we found no allocation notice from the regulator that explains it, so the code below accepts only 06, 08 and 09, like our other guides do for unexplained blocks.

#Which operator holds each prefix?

In Thailand the two-digit prefix doesn't identify the operator. Each block is split between operators at the third or fourth digit, so 081, 089 or 095 can each belong to several. A few examples from libphonenumber's carrier prefix file (66.txt), which still uses the brand names of the time the ranges were assigned:

Two mergers explain the right-hand column. dtac and True completed their amalgamation on 1 March 2023 into True Corporation Public Company Limited (True Corporation, 2023). The two state-owned operators, TOT and CAT Telecom, were merged into National Telecom (NT) in January 2021 (The Nation via Open Development Thailand, 2020). So "DTAC" in the carrier file today means a True Corporation range, and a lookup that returns "TOT" is describing the original holder.

Porting changes the picture further: none of this tells you today's network. Read the table as "who holds the range" and look the number up when the network matters.

#How do I validate a Thai number in code?

Remove spaces and punctuation, rewrite 0066 to +66, parse with full metadata and the default region TH, and keep only mobiles.

Python (pip install phonenumbers):

import re

import phonenumbers


def normalize_th(raw: str) -> str | None:
    """E.164 for a Thai mobile number, or None."""
    s = re.sub(r"[\s().-]", "", raw)
    # "0066..." means +66, but Thailand has several exit codes (001, 006, 009 ...),
    # so a parser with region TH reads "006" as an exit code. Rewrite it first.
    s = re.sub(r"^0066", "+66", s)
    try:
        n = phonenumbers.parse(s, "TH")
    except phonenumbers.NumberParseException:
        return None
    if (not phonenumbers.is_valid_number(n) or phonenumbers.region_code_for_number(n) != "TH"
            or phonenumbers.number_type(n) != phonenumbers.PhoneNumberType.MOBILE):
        return None
    e164 = phonenumbers.format_number(n, phonenumbers.PhoneNumberFormat.E164)
    return e164 if e164[3] in "689" else None  # 06, 08, 09 only, see the prefix table

JavaScript (npm install libphonenumber-js):

import { parsePhoneNumberFromString } from "libphonenumber-js/max";

/** "081 234 5678", "+66 81 …", "0066 81 …" or "+66 081 …" → E.164 for a Thai mobile number, or null. */
export function normalizeTh(raw) {
  // "0066…" means +66, but Thailand has several exit codes (001, 006, 009 …), so region TH reads "006" as one.
  const input = String(raw).replace(/[\s().-]/g, "").replace(/^0066/, "+66");
  const phone = parsePhoneNumberFromString(input, "TH");
  return phone?.isValid() && phone.country === "TH" && phone.getType() === "MOBILE" && /^\+66[689]/.test(phone.number)
    ? phone.number : null;
}

We ran both on 2026-10-18 (Python 3.12 with phonenumbers 9.0.40, Node.js 24 with libphonenumber-js 1.13.13). Both returned an E.164 number for rows 1 to 5 below, including row 3, and nothing for rows 6 to 10. They also agreed on inputs outside the table: +66 08… with the stray 0, 66 8… without a plus and 001 66 8… with a Thai exit code all became the right E.164 number, while 014… and 068… numbers were rejected. The libphonenumber column shows what the library makes of each input on its own, without our two extra rules. The shape regex column tests the pattern most tutorials give, after spaces, dashes and brackets are removed:

Rows 3, 8 and 10 are the ones to remember:

1. Row 3: 0066 passes the regex, but libphonenumber on its own rejects it for the exit-code reason above. Without the rewrite you lose real customers.
2. Row 8: 010 is shaped like a mobile number and passes the regex, but no mobile range starts there, so an OTP sent to it is wasted.
3. Row 10: 060 passes the regex and libphonenumber says it is valid, but as VOIP, not MOBILE. If your sign-up flow only wants mobiles, check the type, not just validity.

Our post on why an E.164 regex is not enough shows the same problem in other countries, and our Python and JavaScript guides cover more languages. For VoIP numbers at sign-up, see VoIP number detection.

#Does number portability change the carrier?

Yes. Mobile number portability (MNP) took effect on 5 December 2010. At first it was limited to Bangkok and to 100 numbers a day per operator, with a fee of THB 99, and full nationwide availability followed in January 2011 (Kasikorn Research Center, 2010). New rules from the National Broadcasting and Telecommunications Commission (NBTC), which The Nation reported on 17 January 2017 as taking effect that week, require operators to complete a transfer in two days instead of three and put the fee at THB 29 (The Nation, 2017). The current NBTC notification on mobile number portability, dated 6 September 2021 and published in the Royal Gazette on 23 September 2021, keeps the limit at two working days, counted from a complete and verified request (Royal Gazette, 2021).

The Thailand row of our MNP atlas:

The 2021 notification replaced the 2009 and 2010 rules, which allowed three working days. Our MNP atlas compares Thailand with other countries. For routing, pricing or fraud rules, look up the current network per number instead of reading the prefix. Our SMS routing with MNP and HLR use case shows where that pays off.

#How are SIM subscribers identified?

Every SIM card is registered to a person, and since 2023 the rules have been tightened again and again to fight phone scams.

Sources: the decree's official English translation (MDES, 2023), Pattaya Mail's report of the NBTC's statements (2024) and Tilleke & Gibbins' summaries of the 2025 amendment (2025) and the 2026 notification (2026). By the end of June 2024, according to the NBTC, only 1,635,407 of the 3,981,251 SIMs affected by the five-SIM rule had been verified, and more than a million SIMs in the over-100 group had already been suspended in February.

Two consequences for businesses:

• Shared liability. Under the decree as amended, banks, payment providers, mobile network operators and other service providers are jointly responsible for losses from technological crimes unless they show they met their regulators' standards (Baker McKenzie, 2025). Expect Thai banks and fintechs to ask more of the phone numbers they rely on for OTPs.
• Suspended outgoing service. A number whose owner missed a verification deadline can lose outgoing calls and SMS first. It may still receive your OTP and look normal to you, while the customer can't reply or call back. Our SIM swap signals post covers the checks that do point to fraud.

#What is the +697 prefix on calls in Thailand?

It marks an incoming call that arrived over internet telephony. In July 2022 the Ministry of Digital Economy and Society said call-centre scammers favour these numbers because they don't have to be registered, and that the NBTC had ordered operators to add +697 to incoming IP calls so people can spot them (The Nation, 2022). Police advice repeated in September 2024 is to reject calls from abroad starting +697 or +698 and to treat +66 calls made over VoIP with suspicion (PRD, 2024). +697 is not a country code and never belongs in a phone field: if one reaches your database, it came from a caller ID, not from a customer.

#Which messaging apps and channels reach people?

SMS reaches every active mobile. Among messaging apps, LINE is the one most Thai businesses build on: in August 2026 LINE Thailand disclosed 56 million users in the country and more than 12 billion conversations with LINE Official Accounts during 2025 (Relevant Audience, reporting LINE's disclosure, 2026). Those are the company's own figures, not an independent measurement, so we don't quote market shares for LINE, WhatsApp, Facebook Messenger or Telegram.

The practical answer is to measure your own opted-in customers: check which apps they are registered on, route each person to the channel they use, and keep SMS as the fallback. Our LINE, Zalo and Botim guide explains how much weight a "not registered" answer carries on LINE, where people also connect by ID and QR code, and our channel-by-country guide shows the method.

#How do I check LINE, WhatsApp or Telegram registration for Thai customers?

Normalise every row first, then run the checks you need per number. The LINE check runs in bulk jobs only; the WhatsApp check and the Telegram check run in real time and in bulk. A check tells you whether a number is registered at the time of the check. It can't tell you whether the person wants your messages:

For a few numbers at a time, use a real-time lookup. This one uses the public sandbox key mv_test_publicSandboxn9ZgneuhR1B9CRfKG3fulym and our test values; the sandbox accepts only those UK drama numbers. With a live key, pass the output of normalize_th():

import os

import requests  # pip install requests

API = "https://api.mobilevalidate.com/v1/lookup"
KEY = os.environ["MOBILEVALIDATE_API_KEY"]


def channels(numbers: list[str]) -> dict[str, dict]:
    """WhatsApp and Telegram registration per number. None means we don't know."""
    r = requests.post(API, headers={"Authorization": f"Bearer {KEY}"}, timeout=15,
                      json={"numbers": numbers, "checks": ["whatsapp", "telegram"], "wait": 5})
    r.raise_for_status()
    out = {}
    for row in r.json()["results"]:
        out[row["e164"]] = {
            name: (c["registered"] if c["status"] == "completed" else None)
            for name, c in (("whatsapp", row["checks"]["whatsapp.registered"]), ("telegram", row["checks"]["telegram.registered"]))
        }
    return out


for number, info in channels(["+447700900001", "+447700900002", "+447700900005"]).items():
    print(number, info)

What the test values return (we ran it against the sandbox on 2026-10-18):

For lists, and for LINE, use a bulk job with a CSV whose numbers are written nationally and default_country=TH:

curl https://api.mobilevalidate.com/v1/jobs \
  -H "Authorization: Bearer $MOBILEVALIDATE_API_KEY" \
  -F file=@customers.csv -F checks=line,whatsapp -F default_country=TH

Two pricing rules apply to Thai lists. LINE is a bulk-only check, so each country in a job is charged at least the price of 500 LINE checks. WhatsApp checks get the bulk price only for groups of at least 132 numbers from the same country in one job. Collect a day's Thai numbers into one job, and send the same body to POST /v1/jobs/estimate first: it is free and shows the maximum cost before anything runs. Unknown or inconclusive results are never charged; see current prices. Rewrite 0066 numbers before uploading, because a CSV written that way can come back as invalid_number.

Use these checks only for numbers you hold lawfully, such as customers and sign-ups. Requests with 20 or more consecutive numbers are refused (403 suspected_enumeration), and our acceptable use policy forbids finding recipients for unsolicited messages. People can object through our opt-out form. Our consent guide covers the legal basis in more detail.

#What are the rules for SMS, calls and personal data?

These summarise the texts and commentary as we read them between 2026-10-16 and 2026-10-18. Thailand has no single anti-spam law; the rules for marketing messages come from the data protection law, the direct marketing law and the NBTC. Not legal advice; ask local counsel how they apply to you.

Penalties are significant: under the PDPA, administrative fines of up to THB 5 million, plus criminal penalties and punitive damages; operating direct marketing without registration can bring up to one year in prison or a THB 100,000 fine.

#What that means for OTP

A one-time passcode the user asked for isn't marketing, but it travels on the same routes and is filtered by the same operators. Keep OTP messages free of offers, send them under a stable sender name, and don't reuse numbers collected for verification for marketing without separate consent. A customer who dialled *137 to stop promotional SMS may also filter more than you expect, so monitor delivery per operator.

#Personal data checks

A registration check on a customer's number is processing of personal data under the PDPA. Record why you run it, keep only the answer you need, and honour objections. Our privacy checklist lists the steps, and is a phone number personal data? explains why the answer is almost always yes.

#What changed recently?

The rows for TH and +66 in our numbering-plan changes dataset, built from libphonenumber's release notes:

Latest numbering-plan updates for TH: 2026-04-22 (v9.0.29), 2024-01-24 (v8.13.29), 2021-11-25 (v8.12.38), 2021-09-22 (v8.12.33), 2021-01-12 (v8.12.16).

Thailand's numbering metadata changes less often than Vietnam's or Malaysia's, but the April 2026 update shows it still moves, so keep your library current. Beyond numbering, the changes that matter are the SIM identity rules: the five-SIM verification of 2024, the 2025 amendment of the Emergency Decree and the NBTC notification of May 2026.

#What can MobileValidate check for Thai numbers?

Generated from our public catalog:

* bulk jobs only. Catalog as fetched on 2026-10-19; the live list is at GET /v1/services.

A lookup returns network and registration facts. It never returns a subscriber's name, ID card number or address, and we don't offer "number details" searches. See MNP lookup, HLR lookup and carrier lookup for the network fields.

#What are the key takeaways?

• Thai mobiles are +66 plus nine digits starting 6, 8 or 9, 0XX XXX XXXX at home; store the E.164 form and strip a stray 0 after +66.
• Rewrite 0066 to +66 before parsing: Thailand has several exit codes (001, 006, 009 …), so a parser set to Thailand misreads 0066.
• 060 and 068 are VoIP, not mobile; check the number type, not just validity.
• The prefix names the range holder (AIS, True Corporation, NT or an MVNO), not the current network: porting has run since December 2010, with a two-day transfer since 2017.
• SIMs are tied to verified identities, with caps and deadlines added in 2024 and 2026; marketing SMS needs PDPA consent, and subscribers can stop unwanted SMS with *137.
• Check LINE, WhatsApp or Telegram registration only for customers you hold lawfully, keep unknown apart from false, and never treat registration as consent.

Platform, operator, regulator and company names are used descriptively. MobileValidate is not affiliated with any of them.