How to Get a Thai Tax ID Number as a Foreigner

If you earn income in Thailand — as an employee, a freelancer, or a business owner — you'll generally need a Thai Tax Identification Number (TIN) to file a personal income tax return. It's a separate number from your passport, work permit, or Thai ID card, and getting one is usually more paperwork-light than people expect.

Who needs one

Broadly: anyone with Thailand-sourced assessable income above the filing threshold, regardless of nationality or visa type. In practice, this covers most foreign employees on a work permit, freelancers invoicing Thai clients, and anyone renting out property in Thailand. If your employer handles payroll through a Thai company, they may already have registered you — check your payslip or ask HR before assuming you need to do this yourself.

What you'll need

• Passport, with your current visa or entry stamp
• Work permit, if you have one
• Proof of Thai address (rental contract, or a letter from your employer)
• A completed Lor Por 10.1 form (the Revenue Department's TIN application form)

Two ways to register

1. In person at a Revenue Department office. Any Area Revenue Office can process a TIN application — you don't need to go to a specific branch tied to your address, though your own district's office is usually the most familiar with foreigner applications.
2. Through your employer. Many companies register new foreign hires for a TIN as part of onboarding, alongside work permit and social security paperwork. If you're employed, this is worth asking about before doing it yourself.

After you have one

Your TIN is what you'll use on your annual PND 90/PND 91 tax return, filed between January and March for the prior tax year. Our Thai Personal Income Tax Calculator estimates what you'll likely owe, and the Tax Refund Estimator checks whether your withheld tax already covers it.

Assumptions & sources

Registration requirements are set by Thailand's Revenue Department and can vary in practice by office — some branches ask for additional documents, particularly for freelancers without a single Thai employer. Confirm current requirements with your local Area Revenue Office, or a Thai accountant, before your appointment.