What Is a Taxpayer Identification Number (TIN)?

Yes. For Thai individuals, the Taxpayer Identification Number is the same 13-digit number as their national ID card, so there is no need to apply for a new one. Companies and partnerships registered with the Department of Business Development use their 13-digit juristic person registration number as their TIN. Anyone who has neither number, such as a foreign national, must apply to the Revenue Department within 60 days of first earning income.

Table of Contents:

What Is a Taxpayer Identification Number (TIN)?
Is the TIN for Individuals and Juristic Persons the Same as the National ID Number?
How to Apply for a Taxpayer Identification Number
How Do You Check a Taxpayer Identification Number?
When Does HR Need Employees' Taxpayer Identification Numbers?
FAQ: Common Questions About Taxpayer Identification Numbers

Is the TIN for Individuals and Juristic Persons the Same as the National ID Number?

A Taxpayer Identification Number is a unique 13-digit number set by the Revenue Department to identify each taxpayer. It is used to file taxes and to deal with government agencies and other relevant organizations. Individuals and juristic persons both have a 13-digit number, but where the number comes from depends on the type of taxpayer. Under Section 3 Ekadasa of the Revenue Code, the Director-General of the Revenue Department has the authority to require taxpayers and payers of income to have and use this number.

The short answer: Thai individuals use the same number as their national ID card, while juristic persons use their juristic person registration number. The table below summarizes the differences.

**Comparing Taxpayer Identification Numbers for Individuals and Juristic Persons**
Topic	Thai individuals	Juristic persons (companies / registered partnerships)	Foreign nationals / ordinary partnerships / bodies of persons
Number used	13-digit national ID number	13-digit juristic person registration number	13-digit number issued by the Revenue Department
Issuing agency	Department of Provincial Administration, Ministry of Interior	Department of Business Development	Revenue Department
Application required?	No, can be used right away	No, the number is assigned at registration	Yes
Application form	—	— (juristic persons that must apply themselves use Form L.P.10.3)	L.P.10.1 (individuals) · L.P.10.2 (ordinary partnerships / bodies of persons)
Deadline	—	Within 60 days of registration or of starting business in Thailand (if filing L.P.10.3)	Within 60 days of first earning taxable income
How to recognize it	First digit is 1–8	Starts with 0	—

Individuals

For individuals, the Taxpayer Identification Number is the same as the 13-digit national ID number issued by the Department of Provincial Administration, Ministry of Interior. There is no need to request a new number from the Revenue Department. Taxpayers can use their national ID number to file taxes and handle other tax matters right away.

Sole proprietors doing business in their own name can also use this number with the Revenue Department. This cuts down on steps and duplicate paperwork, and makes transactions with government agencies and private organizations easier.

Juristic Persons

For juristic persons, whether a company, partnership or other business entity, the Taxpayer Identification Number is the same as the 13-digit juristic person registration number issued by the Department of Business Development on the date the business is registered.

This number is essential for tax operations such as issuing tax invoices, filing tax returns and doing business with both the public and private sectors. It identifies the business for its entire lifetime and serves as important evidence of the organization's transparency and credibility.

How to Apply for a Taxpayer Identification Number

Individuals running their own business whose income reaches the taxable threshold, and new juristic persons that do not yet have a TIN, need to apply for one so their taxes can be handled correctly. The application steps are as follows.

Individuals

For individuals, getting a TIN is simple, because the 13-digit national ID number can be used right away without a new application. Foreign nationals and ordinary partnerships that do not have a national ID number must apply to the Revenue Department within 60 days of first earning taxable income, using these steps:

Choose the right form: Form L.P.10.1 for individuals, or Form L.P.10.2 for ordinary partnerships or bodies of persons. Both can be downloaded from the Revenue Department website.
Prepare supporting documents: such as a passport, alien certificate, or partnership/body-of-persons agreement, as required by the form.
Submit the application at your Area Revenue Office: within 60 days of first earning taxable income.
Receive your 13-digit TIN: to use for filing returns and other tax transactions.

Juristic Persons

Juristic persons such as companies or limited partnerships registered with the Department of Business Development receive a 13-digit juristic person registration number on the day they register, and use it as their TIN for the life of the business. Juristic persons that must apply to the Revenue Department themselves should follow these steps:

Use Form L.P.10.3: the application for a Taxpayer Identification Number for juristic persons.
Prepare supporting documents: such as the company registration certificate or documents showing the start of business operations in Thailand, as required by the form.
Submit to your Area Revenue Office within 60 days: of registering as a Thai juristic person, or of starting business in Thailand in the case of a foreign juristic person.

Applying on time keeps your business compliant with tax law. See the latest forms and details at the Revenue Department, and information on juristic person registration at the Department of Business Development.

How Do You Check a Taxpayer Identification Number?

Your own (Thai individuals): simply look at the 13-digit number on your national ID card.
A business partner's: check their company registration certificate or tax invoice, or search the company name in the business database of the Department of Business Development.
VAT-registered businesses: verify through the online services of the Revenue Department.

Quick Check for Typos

The 13th digit of a national ID number is a "check digit" calculated from the first 12 digits. HR can use it to verify a number before using it in a tax filing.

Multiply the first 12 digits by 13, 12, 11 … down to 2, in order, and add up the results.
Divide the total by 11 and take the remainder.
Check digit = (11 − remainder), keeping only the last digit.

Example: Number 1-2345-67890-12-? → (1×13) + (2×12) + (3×11) + (4×10) + (5×9) + (6×8) + (7×7) + (8×6) + (9×5) + (0×4) + (1×3) + (2×2) = 352 → 352 ÷ 11 leaves a remainder of 0 → 11 − 0 = 11 → last digit = 1. The correct number is 1-2345-67890-12-1 (a fictitious example).

When Does HR Need Employees' Taxpayer Identification Numbers?

As the "payer of income," the employer must use every employee's TIN for payroll tax work, including:

**Payroll Tax Documents That Require Employees' TINs**
Document	Purpose	Frequency
P.N.D.1	Filing withholding tax on employees' salaries	Monthly
P.N.D.1 Kor	Annual summary of each employee's income and tax withheld	Once a year
Withholding Tax Certificate (50 Tawi)	Issued to employees for filing their annual personal income tax	Once a year, and when an employee resigns

If an employee is a foreign national without a Thai national ID number, HR should have them apply for a TIN using Form L.P.10.1 as soon as they start work, so the first month's P.N.D.1 can be filed completely. Thai employees can use their national ID number right away. For an overview, see Personal Income Tax Summary and the 2026 Tax Calendar.

HumanSoft Payroll Software stores each employee's TIN in their employee record and pulls it into P.N.D.1 and 50 Tawi reports automatically, so there is no need to re-enter numbers every month.

FAQ: Common Questions About Taxpayer Identification Numbers

Q: Is the Taxpayer Identification Number the same as the national ID number?

A: Yes, for Thai individuals. They can file taxes with their 13-digit national ID number right away, without requesting a new number from the Revenue Department. Companies and partnerships registered with the Department of Business Development use their 13-digit juristic person registration number instead.

Q: Do foreigners working in Thailand need to apply for a Taxpayer Identification Number?

A: Yes. If they have taxable income in Thailand but no Thai national ID number, they must submit Form L.P.10.1 at their Area Revenue Office within 60 days of first earning income.

Q: Does a company need to apply for its own Taxpayer Identification Number?

A: Companies and partnerships registered with the Department of Business Development do not need a new number. They use the 13-digit juristic person registration number received at registration. Juristic persons that must apply to the Revenue Department themselves use Form L.P.10.3 within 60 days of registration or of starting business in Thailand.

Q: Where can I find a company's Taxpayer Identification Number?

A: Check the company registration certificate or a tax invoice issued by the company, or search the company name in the Department of Business Development's business database. VAT-registered businesses can also be verified through the Revenue Department's online services.

Q: What does HR use employees' Taxpayer Identification Numbers for?

A: To fill in the monthly P.N.D.1, the annual P.N.D.1 Kor, and the Withholding Tax Certificates (50 Tawi) issued to employees. If a number is wrong or incomplete, the tax withheld may not be recorded as a tax credit for that employee.

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