Tax Residency Certificates Thailand

What are R.O. 21 and R.O. 22?

A common concern for foreigners who live, work, invest, or retire in Thailand is how their income will be taxed by the Thai government. Whether you are a Thai citizen or a foreigner, you will file your taxes using the same forms, PND 91 or PND 90. However, if you have income sources from overseas, this money could end up being taxed twice; once by the source country, and again by Thailand when you bring it into the country.

If you wish to avoid double taxation or need proof of residency in Thailand for other tax purposes, forms RO.21 and RO.22 can help you achieve this. The Thai Revenue Department (TRD) provides these forms on request, which can then be submitted to foreign tax agencies and financial organizations.

If you are a taxpayer in Thailand, these documents provide important information about your income and status. They detail your assessable income, the taxes you have paid, and your place of residence for tax purposes. With these forms, you can avoid being overly taxed, prevent double taxation on income from abroad, and open up investment opportunities in Thailand.

This page covers what the R.O. 21 and R.O. 22 forms are, how they can help you, and how to get them.

What is a Thai Form R.O. 21 Document?

Form R.O. 21 is also known as the Income Tax Payment Certificate. It shows how much assessable income you have declared in Thailand and how much income tax you’ve paid in a given calendar year. While related to the R.O. 22 form, it has a separate purpose and application process.

This form proves that you have paid your income taxes in Thailand and is used, among other things, to prevent your income from being taxed twice.

Thailand has many double tax agreements (DTAs) with countries across the world, which ensure that foreign citizens living in Thailand do not have their income taxed by both the Thai government and the taxpayer's home country government at the same time. Depending on your home country’s DTA (if they have one) with Thailand, your income may be exempted completely from home taxes if it is taxed by the TRD, or you may be eligible for a lower tax rate.

Form R.O. 21 proves that you have already paid tax on your income in Thailand and thus cannot be taxed by your home government, or are eligible to pay a lower tax rate. The document is widely accepted across the globe, as it has an official Revenue Department stamp and a document number that can be cross-referenced with the TRD from anywhere.

What is a Thai Form R.O. 22 Document?

Form R.O. 22 is a document also known as the Tax Residency Certificate. It proves that you are a tax resident in Thailand. To be considered an official "Thai tax resident," you must have been present in the country for at least 180 days in the preceding calendar year (which is the same as the tax year).

Form R.O. 22 shows that you legally live in Thailand, and it is also important for double tax treaty purposes. It proves you reside in Thailand and are taxed by its government, helping you claim relief under your home nation’s double tax treaty with Thailand, if it has one.

Whether or not you are a Thai tax resident changes from year to year. You must reside in Thailand for 180 days out of the calendar/tax year, but the counter resets at the beginning of each year. This means that you will need a new form R.O. 22 each year to continue leveraging its benefits.

How to Use Forms R.O. 21 and R.O. 22

Most foreigners in Thailand use these forms to prove their tax payments and residency status in order to qualify for relief under Thailand’s DTAs. You must prove that your income has already been taxed once so that it cannot be taxed again, or that you are eligible to pay reduced rates on certain taxes.

Here are some examples of how these documents can help you:

• Many international pension funds, investment platforms, and payroll departments must lower withholding tax rates on certain citizens living in Thailand due to DTAs. However, they will not offer this reduced rate unless you present a valid R.O. 22 document. 
• US brokerage firms usually withhold a flat 30% on dividends and royalties. Presenting a current R.O. 22 can drop that rate to 15% or less. 
• You can often get a credit or refund on your home country’s income taxes for Thai taxes you've previously paid, provided you send in form R.O. 21. 
• Investors from countries with Thai DTAs can get lower tax rates on dividends, royalties, and bond coupons. 
• Remote workers who show proof of residence with a form R.O. 22 to content platforms can avoid blanket royalty taxes. 
• Entrepreneurs who remit profits from a Thai company to an offshore holding structure can show that they are following the rules and avoid audits and penalties. 
• Long-term visa holders can improve their chances of being approved for a visa renewal by showing a clear record of tax payments. 
• Due to increased criminal activities involving scammers and "mule accounts" originating from foreign countries, Thai banks have put more restrictions on foreigners opening bank accounts. New customers can improve their odds of approval and skip further paperwork if they show a current R.O. 22, but policies vary by bank.

As you can see, these documents are useful in a wide range of situations and are valuable tools for any foreigner drawing an income while living in Thailand.

How to Get Forms R.O. 21 and R.O. 22

To be eligible to acquire one of these documents, you must be a taxpayer in Thailand, which requires:

1. Becoming a tax resident by spending 180 days or more within Thailand’s borders
2. Acquiring a Thai tax identification number (TIN)
3. Filing an annual income tax return (form PND 90 or PND 91, depending on your sources of income)
4. Paying any taxes you owe

Once you have successfully filed a return for your income taxes, you can acquire forms R.O. 21 and R.O. 22 for the year you filed. So, for example, after you pay your taxes for 2024 during Thailand’s 2025 tax season, you can apply for both forms that prove you were a taxpayer in 2024 and paid your taxes accordingly.

If you file late, you can still get certificates for previous years, but you have to bring your returns up to date and pay any outstanding surcharges.

Applying for Forms R.O. 21 and R.O. 22 at the Thai Revenue Department

To acquire these forms, you must go to a Revenue Department office, ideally the one that has jurisdiction over your place of residence. You’ll need to fill out a request form and provide some supporting documentation in person, or have an authorized agent do so on your behalf.

If you do not speak or read Thai, you may wish to secure assistance with the requests for these forms. There is no guarantee that English-speaking services will be available at the Revenue Department office, and official request forms will be in the Thai language. Any mistakes on your forms or documentation, and your request could be delayed or outright rejected.

When you go to the Revenue Department office, you will need to bring:

• Copies of your passport biodata page, as well as all pages that show an immigration stamp for the year in question (to prove you were in Thailand for at least 180 days of the tax year)
• The payment receipt from the Revenue Department for your paid taxes
• A completed request form (these are available at the office, but you can print one out and complete it beforehand to save time)

Be aware that there are separate request forms for both R.O. 21 and R.O. 22, but you can request both at the same time.

Companies can also ask for an R.O. 22, but only if they are registered in Thailand or have their main office here and are up to date on all of their Thai corporate tax filings.

It usually takes from four to five weeks for the Revenue Department to process your requests for forms R.O. 21 and R.O. 22. You will need to pick up the originals in person, unless your Revenue Department office provides return mail services, which some but not all locations offer. Both forms will be in the English language.

Legalizing Forms R.O. 21 and R.O. 22 for International Use

If you intend to use these forms abroad, you may have to get them legalized by the Thai Ministry of Foreign Affairs (MFA). However, forms R.O. 21 and R.O. 22 come with official stamps from the TRD, so usually this step is not required.

Check with the international requesting authority to determine if these forms require legalization or any additional certifications before they can be accepted. If further legalization is required, you will need to submit them to the MFA along with a separate application for legalization.

The MFA will certify that these documents are official and legally binding in Thailand with a consular red ribbon. In some situations, you must next go to your embassy for a consular attestation. Again, this step should not be necessary, but it is possible the organization/agency you submit R.O. 21 and R.O. 22 to requires it.

Consulting and Application Services for Forms R.O. 21 and R.O. 22 in Thailand

If you require a form R.O. 21 or R.O. 22, but aren’t sure if you qualify or where to start, get in touch with Siam Legal’s tax advisors. We are a full-service law firm that has been assisting foreigners with their legal and immigration needs in Thailand for over 20 years. We employ a full team of local and international tax advisors to assist expat clients with tax issues concerning both Thai and foreign income sources.

Our tax team will walk you through the process of obtaining these forms and how best to utilize them to reduce your tax burdens, Thai or otherwise. We can also handle the requests for forms R.O. 21 and R.O. 22 on your behalf, saving you time and minimizing the risk of delay or rejection.

Contact Siam Legal today, and we’ll provide guidance on these forms and any other personal or corporate tax matters you might have so that we can help you legally minimize your tax burden and avoid penalties from the Thai Revenue Department.