For people relocating from Thailand to the United States

Moving to the US From Thailand: Your First US Tax Year

Before your first US tax return after leaving Thailand, three questions matter: when you became resident, whether the treaty makes you resident somewhere else, and what to report from Thailand.

Substantial presenceGreen card testDual-status yearTie-breakerSocial security

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Quick answer

When does someone moving from Thailand start paying US tax on worldwide income?

From the residency starting date: the first day in the US in a year you meet the substantial presence test, or the first day as a permanent resident under the green card test (IRS Pub 519). Before that you are a nonresident, so the first year is usually dual-status. If you are also resident in Thailand, Article 4 (Residence) of the treaty decides which country you are resident in for treaty purposes.

Prepared by Illuminous Accounting · Sources checked November 11, 2026

At a glance

When you become US resident: Green card test or substantial presence test (Code section 7701(b))
First year: Usually dual-status: nonresident, then resident
Treaty tie-breaker: Article 4 (Residence)
Social security agreement: None on the SSA list
Accounts in Thailand: FBAR, Form 8938 and PFIC rules can apply once resident

The residency starting date

Expect your first year to have two halves. Income from Thailand before you became resident is generally outside US tax unless it is US-source; income after the residency starting date is taxed worldwide (IRS Pub 519). The starting date is your first day in the US in that year under the substantial presence test, or your first day as a permanent resident under the green card test. People who arrive near year end may be able to opt in early under the first-year choice. Getting the date right decides which Thai salary, bonuses and investment income the IRS sees.

Arriving from Thailand: which test applies

There is no form that makes you a US tax resident. It happens automatically under Code section 7701(b) once you pass either test (IRS Pub 519). A green card does it from the first day you are in the US with permanent resident status. Without one, the substantial presence test does it once you have 31 days this year and 183 weighted days over three years.

Someone arriving from Thailand with no earlier US days needs to arrive by early July and stay for the rest of the year to pass the substantial presence test in the first year. The calculator shows the date for your arrival.

The treaty tie-breaker

Article 4 (Residence) of the treaty has the tie-breaker for someone resident in both countries: it looks first at where you have a permanent home available, then at the further tests the article lists, in the order it sets them.

Point	What it means
Who uses it	People resident in both Thailand and the US under each country's own rules, typically in the year of the move
How it is claimed	Form 8833 with the US return, under Treas. Reg. section 301.7701(b)-7 (IRS)
Risk for green card holders	Long-term residents may be treated as expatriated under section 877A

Reporting what you keep abroad

Do not close everything in Thailand in a hurry, and do not forget it either. As a US resident you report foreign accounts on the FBAR and Form 8938 when they pass the thresholds, and many investment funds bought in Thailand fall under the PFIC rules (IRS). Details: FBAR and FATCA; Form 8938.

Treaty and law references

Treaty

The IRS lists the 1996 income tax treaty, signed November 26, 1996. General effective date (IRS Table 3): treaty Jan. 1, 1998 (IRS treaty documents for Thailand; treaty text; IRS Table 3).
Residence and tie-breaker: Article 4 (Residence).
Saving clause: Article 1 (Personal Scope).
Article 20 (Pensions and Social Security Payments), pensions.
Article 25 (Relief from Double Taxation), relief from double taxation.
Article 16 (Dependent Personal Services), employment income.

US law

US residency tests and starting dates: Code section 7701(b) (IRS Pub 519).
Treaty residence for dual residents: Treas. Reg. section 301.7701(b)-7, Form 8833 and section 6114; long-term residents: section 877A (IRS Form 8833).
Social security agreements: SSA list.

The rules of Thailand on leaving the country also apply; check them with a local adviser.

How we help

Gurleen Kaur, CPA licensed in British Columbia and Washington State, prepares the first-year dual-status return, treaty disclosures and the reporting for accounts left in Thailand. Every engagement starts with a written quote after we review your dates and income. Also see Form 1040-NR.

Moving from other countries

All countries: moving to the US, by country. From Canada: moving from Canada to the US.

Common questions

Does my visa decide my US tax residence after moving from Thailand?

When you meet the green card test or the substantial presence test (31 days this year and 183 weighted days over three years). Your residency starting date is generally your first day in the US that year, or your first day as a permanent resident.

What if I am resident in both Thailand and the US?

Article 4 (Residence) of the treaty breaks the tie, starting with where you have a permanent home. Claiming treaty residence in Thailand on a US return needs Form 8833.

Do I report my accounts in Thailand after moving to the US?

Once you are a US resident, yes: the FBAR when foreign accounts total more than US$10,000, Form 8938 above higher thresholds, and PFIC rules for many foreign funds.

Is there a US social security agreement with Thailand?

No, Thailand is not on the SSA list of agreement countries.

Sources

Every rule and figure on this page links to the IRS, CRA or other official source it comes from. Amounts change; we re-check them before each engagement.

Gurleen Kaur, CPA licensed in British Columbia and Washington State. Last updated November 11, 2026. This page is general information, not tax or legal advice for your situation.

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