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Yes, in general terms. If you are a US citizen or another kind of US person with a bank account in Thailand, your bank identifies US persons among its customers and reports those accounts to the Thai Revenue Department. The Revenue Department then passes the data on to the IRS through the IRS's secure exchange system, IDES, under the Model 1 FATCA agreement between Thailand and the United States, in force since April 2024. FATCA is a reporting rule, not a tax: it changes nothing about what Thailand itself taxes. Your own US filings — the FBAR and Form 8938 — stay due if you meet their separate conditions, whatever your bank reports.
In short
- The Thailand–US Model 1 FATCA agreement has been in force since April 2024 (29 April, per the US Treasury).
- Your bank reports to the Thai Revenue Department, which forwards the data to the IRS — the bank does not send anything to the IRS directly.
- If your bank sends you a Form W-9, ask it what the request is for and how to fill it in.
- FATCA is reporting, not a tax. It does not add to or reduce what Thailand taxes you on.
- If you meet their separate conditions, you file the FBAR and Form 8938 yourself. One does not replace the other, and neither replaces your Thai tax return.
What FATCA is and how it works in Thailand
FATCA is a US law that requires foreign financial institutions to identify and report accounts held by US persons. Thailand and the United States signed a Model 1 intergovernmental agreement in 2016, and it has been in force since April 2024. Under a Model 1 agreement, a Thai bank does not report to the IRS itself: it reports to its own government, the Thai Revenue Department, which then exchanges the data with the IRS.
On the Thai side, the agreement rests on the FATCA Implementation Act B.E. 2560, a royal decree from 2021 and ministerial regulations from 2023. The first exchange of data under the agreement began in June 2024.
FATCA only moves information. It does not create a new Thai tax, and it does not exempt anyone from an existing one. What Thailand taxes is set separately by the Revenue Code and by the rule on remitted foreign income, which applies the same way whether or not you are a US citizen.
What Thai banks pass to the IRS
The path your account data takes is fixed by the agreement: bank → Thai Revenue Department → IDES → IRS. We have not seen an official Thai list of the exact fields a bank sends or a reporting threshold in US dollars, so be careful with figures you see quoted online — we cannot confirm them from a primary source, and we would rather say that plainly than guess.
One detail does matter for what you will see from your bank. Under IRS Notice 2024-78, for the years 2025 through 2027 a missing US taxpayer number on a pre-existing account does not by itself make a bank's reporting significant non-compliance under the Model 1 agreement, provided the bank meets all the notice's conditions, including asking the account holder for that number every year and reporting the account holder's date of birth. This may be why your bank writes to you each year asking for your US taxpayer number — if yours is already on file and the bank still asks, check with the bank why. If your bank has sent you a letter like this, send it to us — we can explain in plain terms what it is asking for and why.
FBAR and Form 8938: what you file yourself
A bank's report to the Thai Revenue Department has nothing to do with your own US filing duties. Two separate filing requirements may apply, depending on your circumstances and asset values:
| FBAR | Form 8938 | |
|---|---|---|
| Who files | US persons with a financial interest in, or signature authority over, foreign financial accounts that together exceeded USD 10,000 at any point in the year (IRS FBAR rules) | US persons who meet the IRS's living-abroad test and must file a US return, once specified foreign financial assets exceed USD 200,000 at year-end or USD 300,000 at any point (USD 400,000 / 600,000 if filing jointly) (IRS Form 8938 summary) |
| Where | Filed online with FinCEN | Filed together with your US tax return, with the IRS |
| Deadline | 15 April, automatic extension to 15 October | Same as your tax return |
| Penalty for a non-wilful miss | Up to about USD 16,500 per report (not per account), adjusted yearly | USD 10,000; up to USD 60,000 after an IRS notice |
The two forms test different things — a total balance for the FBAR, the combined value of specified foreign financial assets for Form 8938 — so you can owe one, both or neither depending on your numbers. Before you file either one, we advise:
- Pulling year-end and highest-balance statements for every foreign account, Thai and otherwise.
- Keeping records that show where the money came from and when you earned it — this matters as much for your Thai filing as for your US one.
- Checking both thresholds separately; crossing one does not mean you crossed the other.
- Confirming with a US tax preparer which forms apply to your situation this year.
- If you missed a past year and it was not wilful, looking at the IRS Streamlined Foreign Offshore Procedures, which cover three years of returns and six years of FBARs for US persons who meet its non-US-residence conditions.
FATCA vs CRS
FATCA and the Common Reporting Standard (CRS) are often confused, and the confusion is understandable: both move bank data between countries. They are not the same thing.
| FATCA | CRS | |
|---|---|---|
| Parties | Bilateral: Thailand and the United States | Multilateral: participating jurisdictions |
| Who is reported | US persons | Tax residents of Thailand's CRS partner jurisdictions |
| Thailand's role | Reports to the US via the Thai Revenue Department | Has exchanged data under CRS since September 2023 |
If you are a US person who is also tax resident somewhere else, treat FATCA and CRS as separate questions and check each on its own terms.
Why the bank asks for a W-9
If your bank sends you a Form W-9, ask it what information it needs and why: in general, this kind of form tells a bank a customer's US taxpayer identification number and confirms US-person status for FATCA purposes.
Individual banks set their own internal rules about what they ask for and when, and no general rule requiring a Thai bank to refuse or close an American's account over FATCA is confirmed. If a bank tells you otherwise, ask it to point you to the rule it is relying on. Our advice is practical: answer the bank's requests, keep your US taxpayer number on hand, and ask what documents it wants before you need them urgently. If a bank's request looks unusual, send it to our lawyers — we can look at exactly what is being asked and why.
What to do next
FATCA changes nothing about your Thai tax bill. What does matter is the rule on remitted foreign income: under Departmental Instruction Por. 161/2566, a Thai tax resident — someone who spends 180 days or more in Thailand in a calendar year — pays Thai tax on assessable foreign-sourced income earned on or after 1 January 2024, in a year when they were Thai tax resident, once that money is brought into Thailand; income earned before 2024, savings, and some income covered by a treaty are treated differently (Por. 161/2566, Por. 162/2566). That applies to a US citizen in Thailand the same as to anyone else. The US–Thailand tax treaty can also limit what Thailand taxes on specific items — for example, US Social Security paid to a Thai resident is taxable only in the United States — while its saving clause separately preserves the US's own right to tax its citizens on their worldwide income.
If you already file a Thai return, this sits alongside your annual PND 90 filing. If you are not sure whether a transfer you are planning counts as assessable income in Thailand, our team can go through it with you, and we fix the cost before we start. For a sense of how this plays out for someone juggling two tax systems, our typical case of a US citizen with two tax residencies — a situation assembled from practice, not one client's file — shows one way the numbers were worked out year by year.
For a wider look at how Thailand taxes foreign income and what to plan for as a US person living here, start with our tax advice for foreigners.
