Taxes for Foreign Workers in the U.S.: SSN, ITIN, and What Gets Withheld

Your first U.S. paycheck will probably be smaller than the wage you agreed to, and that is normal. U.S. employers withhold taxes from pay, and as a foreign worker you also need the right taxpayer number and, usually, to file a tax return. This guide explains the system in plain language so nothing surprises you.

First: SSN or ITIN?

Social Security Number (SSN). If you are authorized to work in the U.S., you should apply for an SSN, it is the standard taxpayer and identity number for workers. You apply through the Social Security Administration (ssa.gov), free of charge, usually shortly after arrival; in many visa processes you can request it as part of your visa application. Your employer needs it for payroll, and you will use it for banking and much else.

Individual Taxpayer Identification Number (ITIN). An ITIN is for people who have U.S. tax obligations but are not eligible for an SSN, for example certain dependents or spouses. You apply to the IRS with Form W-7. An ITIN does not authorize work and does not change immigration status; it exists only for tax administration. Beware of anyone selling "ITINs that let you work", that is not what an ITIN is.

What comes out of your paycheck

Typical withholdings from a U.S. paycheck:

Item	What it is
Federal income tax	Withheld based on the Form W-4 you fill out when hired; the exact amount depends on your income and situation.
Social Security and Medicare (FICA)	Flat-percentage payroll taxes shared between you and your employer. Some nonresident visa categories (for example certain students and exchange visitors on F-1 or J-1) are exempt; most work-visa employees pay them.
State income tax	Depends on the state. Some states (like Texas and Florida) have no state income tax; others withhold their own tax.
Local taxes	A few cities and counties add small local taxes.

Your pay stub lists each deduction. Keep every pay stub, they are your proof of earnings and withholding, and they matter if there is ever a dispute.

Resident or nonresident for tax purposes?

U.S. tax law splits foreign workers into resident aliens and nonresident aliens, and this is about tax rules, not immigration status. Broadly, if you spend enough days in the U.S. (the "substantial presence test"), you are taxed like a resident, on worldwide income, with the same forms most Americans file (Form 1040). Nonresidents are generally taxed only on U.S. income and file Form 1040-NR. The day-counting rules and exceptions are detailed, and getting this wrong is common, IRS Publication 519 at irs.gov is the official guide, and this is one area where a tax professional's help is often worth it for your first year.

Filing a tax return: usually required, often good for you

Most workers must file a federal tax return by the deadline in April covering the previous year. Around late January, your employer sends you a Form W-2 showing your wages and everything withheld. Filing matters for two reasons:

• You may get money back. Withholding is an estimate. If too much was withheld, which is common for partial-year and seasonal workers, filing is how you get the refund.
• Compliance protects your future. A clean tax record helps with future visa applications, green card processes, and simply staying out of trouble.

Tax treaties between the U.S. and many countries can reduce taxes for certain workers; whether one applies to you depends on your country and situation, check irs.gov or ask a professional.

Scams and bad "helpers"

• The IRS does not call or message you demanding immediate payment by gift card, wire, or crypto. Those calls are scams, hang up.
• Use reputable tax preparers. Avoid anyone who promises a specific big refund before seeing your documents or wants a percentage of your refund.
• Never let an employer pay you "off the books" to "save taxes." It deprives you of proof of income, workplace injury coverage, and legal protection, and the risk falls mostly on you.

If you are still preparing your move, our overview of the documents you need to work in the USA covers the paperwork that comes before your first paycheck.

This article is general information, not tax or legal advice. Tax rules change, and your situation, visa category, days of presence, home country treaty, determines what applies. Check official sources at irs.gov and ssa.gov, or consult a qualified tax professional.

Understanding the system is easier when you have a real employer relationship from day one, with proper payroll and pay stubs. On Workmerica, U.S. employers who hire from abroad contact workers directly, no agencies, no fees for workers. Create your free profile, it is free and takes no credit card.