How to File a US Tax Return Step by Step (2026)

Filing a US tax return as an immigrant or international resident feels daunting, but it follows a clear sequence anyone can learn. Get it right and you may recover thousands of dollars in over-withheld federal income tax. Get it wrong and you face IRS penalties, interest that compounds from the original deadline, and a paper trail that can surface years later during a green card interview or citizenship petition. This guide walks you through every stage — from establishing your tax residency status to pressing submit — with close attention to the cross-border details that general tax software and generic guides routinely skip.

STANDARD FILING DEADLINE (MOST FILERS)
April 15
Verify the exact date for the current tax year at IRS.gov; the date shifts when it falls on a weekend or holiday

AUTOMATIC EXTENSION PERIOD
6 months
Form 4868 grants extra time to file, not extra time to pay any tax owed — interest accrues from the original deadline

OVERSEAS FILER AUTOMATIC EXTENSION
June 15
US citizens and resident aliens living outside the US on the deadline date get an automatic 2-month extension; attach a statement to your return explaining eligibility

Figures refreshed 12 Aug 2026

The financial stakes here are larger than most new filers expect. A wage earner on an H-1B visa who never claims the student loan interest deduction, the foreign tax credit, or an education credit can overpay the IRS by a four-figure sum every single year. On the other side, a self-employed immigrant who overlooks quarterly estimated payments can face a failure-to-pay penalty, a separate failure-to-file penalty, and interest on top of both — which is why tax relief services, IRS installment agreements, and international tax attorneys are a multi-billion-dollar industry in the United States. Filing a US tax return is mandatory for most people living and working in America, and for many US citizens and green card holders living abroad. The process is logical: determine whether you must file, gather your documents, choose the right form, calculate your tax, and submit on time. For immigrants and internationals, four additional layers apply — tax residency status, your taxpayer identification number, foreign account reporting, and treaty eligibility — and this guide covers all of them.

Why Your 2026 US Tax Filing Carries Extra Weight

Several developments make 2026 a particularly important year to get this right.

The IRS has continued expanding its direct e-file infrastructure, meaning more filers can submit returns at no cost through official channels rather than paying for commercial tax preparation. At the same time, enforcement around FATCA (the Foreign Account Tax Compliance Act) and FBAR reporting has intensified, supported by widening data-sharing agreements between the US and foreign financial institutions. If you hold accounts overseas — in your home country or a third country — those accounts are increasingly visible to the IRS whether or not you disclose them.

For immigrants specifically, there is an added dimension. Public charge rules and immigration benefit adjudications can touch on financial history, and an unfiled or incorrect return can complicate visa renewals, green card applications, and naturalization in ways that go well beyond a penalty notice. If you are managing an investor or employment visa alongside a US business, specialist support matters — resources such as Best CPAs for Foreign-Owned US Businesses in 2026: Tax Filing, FATCA, and ITIN Help can point you toward accountants who work with foreign-owned entities daily.

Step 1: Confirm Whether You Are Legally Required to File

Before anything else, establish whether you have a filing obligation. The answer depends on three things: your tax residency status, your filing status, and your gross income.

Resident Alien vs Non-Resident Alien: The Test That Decides Your Tax Bill

The IRS does not use your immigration visa category to decide how to tax you. It applies two tests instead.

Green Card Test: If you held a lawful permanent resident card at any point during the tax year, you are a resident alien for tax purposes.

Substantial Presence Test (SPT): If you were physically present in the US for at least 31 days during the current year, and 183 days when counting all days present in the current year plus one-third of the prior year plus one-sixth of the year before that, you meet the SPT and are generally treated as a resident alien.

If you arrived mid-year and crossed the SPT threshold, you may be a dual-status alien — resident for part of the year and non-resident for the rest. This is one of the more complex scenarios in US tax law, and one where the cost of a specialist CPA is usually far lower than the cost of getting it wrong.

Income Thresholds and When Filing Pays Even If You Don’t Have To

The IRS sets minimum gross income levels below which a return is not required for most filers. These thresholds adjust annually and vary by filing status and age. Always verify the current figure in IRS Publication 501 or the current year’s Form 1040 instructions.

Even if your income falls below the threshold, filing is often worth it. If federal income tax was withheld from your wages, a return is the only way to get that money back. Refundable credits work the same way — they can produce a refund larger than the tax you paid.

Step 2: Get Your SSN or ITIN Before You File

Every US tax return requires either a Social Security Number (SSN) or an Individual Taxpayer Identification Number (ITIN).

SSN: Issued by the Social Security Administration to citizens, permanent residents, and certain visa holders authorised to work.

ITIN: Issued by the IRS via Form W-7 to individuals not eligible for an SSN who have a US tax filing requirement — including non-resident aliens with US income and dependants claimed on a return. For a full walkthrough, see ITIN Application Process for Business Owners 2026.

One point to be clear on: an ITIN is a tax processing number only. It does not authorise work, does not confer immigration status, and does not make you eligible for Social Security benefits. Some tax credits, including the Earned Income Tax Credit, require an SSN for the taxpayer and any qualifying child.

Step 3: Gather Your Documents Before Opening Any Tax Software

Rushing into tax preparation software without your paperwork is one of the most common sources of costly errors and amended returns. Collect the following first.

Income Documents

• Form W-2: Wages from US employers, issued by late January
• Form 1099-NEC / 1099-MISC: Freelance, contract, or miscellaneous income
• Form 1099-INT / 1099-DIV: Interest and dividends from US bank and brokerage accounts
• Form 1099-B: Proceeds from selling stocks or other securities
• Form 1042-S: Income paid to non-resident aliens subject to withholding, often from employers, universities, or financial institutions
• Foreign income documentation: Pay stubs, bank statements, or employer letters for income earned abroad, relevant for resident aliens reporting worldwide income

Deduction and Tax Credit Documents

• Mortgage interest statements (Form 1098) if you own a home
• Student loan interest statements
• Charitable donation receipts
• Health insurance premium records, if relevant to premium tax credit claims
• Records of state and local taxes paid, for the SALT deduction
• Business expense records if self-employed

Prior-Year Information

• Last year’s tax return, particularly your Adjusted Gross Income, which the IRS uses to verify your identity when e-filing
• Any IRS notices received during the year

Foreign Account Information

• Account numbers, financial institution names, and maximum balances for any foreign bank or investment accounts, needed for FBAR (FinCEN 114) and potentially Form 8938

Step 4: Choose the Right IRS Form and Schedules

The Main Return

Resident aliens and US citizens file Form 1040. There is no longer a simplified 1040-EZ or 1040-A; everyone uses the same base form, though attached schedules vary.

Non-resident aliens file Form 1040-NR, which has different sections reflecting the income categories taxed for NRAs.

Key Schedules to Know

If you own a US LLC or corporation, the business tax return is separate from your personal return. See How to File US Business Taxes as a Non-Resident Owner in 2026: Form 5472, 1120, and Penalties Explained for that process.

Step 5: Calculate Taxable Income, Tax Credits, and Your Refund

This is the arithmetic heart of your return, and the stage where most refunds are won or lost.

1. Total Gross Income — All income from all sources, worldwide for resident aliens and citizens
2. Above-the-Line Deductions — Subtract eligible adjustments such as student loan interest, contributions to certain retirement accounts, and the self-employment tax deduction, to reach Adjusted Gross Income (AGI)
3. Standard Deduction or Itemised Deductions — Subtract whichever is larger. The standard deduction adjusts annually for inflation; verify the current figure in the Form 1040 instructions at IRS.gov. Most filers take the standard deduction. Note that non-resident aliens generally cannot claim it and must itemise using Schedule A.
4. Taxable Income — AGI minus deductions, and any qualified business income deduction if applicable
5. Tax Calculated — Apply the current marginal tax brackets. The IRS publishes these in Publication 17 and the Form 1040 instruction booklet.
6. Tax Credits — Subtract eligible credits such as the child tax credit, education credits, and the foreign tax credit. Credits are more valuable than deductions because they cut your tax dollar for dollar.
7. Payments Already Made — Subtract withholding shown on your W-2 or 1099 and any estimated tax payments made during the year
8. Refund or Amount Owed — The difference is either refunded to you or due by the deadline

Illustrative Example: Single Wage-Earner on an H-1B Visa

The following is illustrative only. Figures are hypothetical and do not constitute tax advice.

Aisha arrived on an H-1B visa and was present in the US for the full calendar year, satisfying the Substantial Presence Test. She is treated as a resident alien. Her employer paid a salary and withheld federal income tax throughout the year.

• Wages (W-2 Box 1): $72,000
• Interest income (1099-INT): $400
• Gross income: $72,400
• Student loan interest deduction: –$1,800
• AGI: $70,600
• Standard deduction (illustrative; verify current amount): –$14,600
• Taxable income: $56,000
• Tax calculated (illustrative bracket rates): roughly $7,800
• Federal withholding already paid (W-2 Box 2): $8,500
• Refund: roughly $700

Aisha files Form 1040 with Schedule B for her interest income and receives a modest refund.

Illustrative Example: Freelancer with a Foreign Bank Account

Illustrative only.

Marco moved to the US on an O-1 visa, satisfies the SPT, and does freelance video production for both US and non-US clients. He also keeps a bank account in his home country.

• US client income (1099-NEC total): $55,000
• Foreign client income (no withholding): $18,000
• Gross income: $73,000 — resident alien, worldwide income
• Self-employment tax deduction: roughly $5,150
• AGI: roughly $67,850
• Standard deduction (illustrative): –$14,600
• Taxable income: roughly $53,250
• Tax calculated: roughly $7,200
• Self-employment tax (Schedule SE): roughly $10,300
• Foreign tax credit, having paid local tax abroad (Form 1116): –$2,100
• Total tax after credit: roughly $15,400
• Estimated payments made during year: $12,000
• Amount owed at filing: roughly $3,400

Marco also needs to file an FBAR if his foreign account’s maximum balance exceeded the applicable threshold at any point during the year. He files Form 1040 with Schedules B, C, SE and Form 1116, and submits his FBAR separately through FinCEN’s online system.

Step 6: File Your Return — Free File, Tax Software, or a CPA

E-Filing vs Paper Filing

The IRS strongly prefers electronic filing, and for most people it is faster and more accurate.

• IRS Free File: Available to filers below an income threshold (verify eligibility at IRS.gov/freefile). Guided software at no cost.
• IRS Direct File: The IRS’s own e-file tool, expanded in coverage for recent filing seasons. Check which states and income types it currently supports.
• Commercial Tax Software: Products such as TurboTax, H&R Block and TaxAct handle complex situations but charge fees for certain forms and features.
• Tax Professional: A CPA, IRS enrolled agent, or licensed tax preparer. Particularly valuable for non-resident returns, treaty claims, FATCA and FBAR situations, or self-employment with foreign income.
• Paper Filing: Still accepted, but slower and more prone to transcription errors. Some non-resident and amended returns may still require it.

Signing Your Return

An e-filed return is signed using your prior-year AGI as an identity verification code, or an IRS-issued PIN. A paper return requires a physical signature. Unsigned returns are invalid.

Paying Tax Owed and IRS Payment Plan Options

If you owe, payment is due by the filing deadline even if you requested an extension to file.

• IRS Direct Pay by bank transfer, no fee
• Debit or credit card, with a third-party processor fee
• Electronic Funds Withdrawal when e-filing
• Check or money order with a payment voucher (Form 1040-V)
• IRS Online Account to request an installment agreement if you cannot pay in full

If you cannot pay the full balance, applying for an installment agreement is almost always better than not filing. Non-filing carries its own penalty on top of the unpaid tax.

Step 7: FBAR and FATCA Reporting for Foreign Bank Accounts

This step sits outside your tax return but is closely linked to it, and it is where penalties get expensive fastest.

FBAR (FinCEN Form 114)

If you had a financial interest in, or signature authority over, one or more foreign financial accounts, and the aggregate maximum value exceeded the applicable threshold at any time during the year (verify the current amount at fincen.gov), you must file an FBAR. It goes through FinCEN’s BSA E-Filing System, not the IRS, and is due on the same date as your tax return with an automatic extension to October.

Form 8938 (FATCA)

If you hold foreign financial assets above the applicable thresholds — which vary by filing status and whether you live in or outside the US — you attach Form 8938 to your return. FBAR and Form 8938 can overlap but are not substitutes. You may need both.

Step 8: Extensions, Deadlines, and Late Filing Penalties

Extension to file is not extension to pay. If you owe tax, estimate it and pay by the original deadline to avoid failure-to-pay penalties and accruing interest. Form 4868 buys six months of filing time only.

Costly Tax Filing Mistakes Immigrants Make

1. Filing as a non-resident when you are actually a resident alien. Run the Substantial Presence Test before choosing your form. If you arrived mid-year, count every day carefully using IRS Publication 519.

2. Forgetting to report foreign income. Resident aliens must report worldwide income. Salary, freelance pay, rental income or pension from outside the US belongs on your return even if you never moved the money to a US account.

3. Missing the FBAR or Form 8938 filing. Add a foreign account checklist to your pre-filing routine. Penalties for non-filing can substantially exceed any tax saved by overlooking these forms.

4. Claiming the standard deduction as a non-resident alien. Non-resident aliens, with limited exceptions such as residents of certain treaty countries, must itemise. Review Schedule A and Publication 519.

5. Using an expired or incorrect ITIN. ITINs unused on a return for three consecutive years, or issued before a certain year, expire. Renew with Form W-7 well ahead of filing season.

6. Not keeping records of tax paid abroad. If you paid income tax to a foreign government you may qualify for the Foreign Tax Credit (Form 1116), which directly reduces your US tax bill. Without documentation, you cannot claim it.

7. Ignoring state tax obligations. Most states with an income tax have their own filing requirement, separate from and in addition to the federal return. Check the revenue department website for every state where you lived or worked.

8. Filing late out of uncertainty rather than asking for help. File an imperfect return on time and amend it later with Form 1040-X if needed. Penalties for not filing are generally harsher than penalties for minor errors later corrected.

How Your Visa Status Affects Tax Residency and Immigration Applications

Your visa category does not determine tax residency — the SPT and Green Card Test do — but it provides important context.

• H-1B, L-1 and O-1 holders present for a full year almost always meet the SPT and file Form 1040 as resident aliens.
• F-1 and J-1 students and exchange visitors are exempt individuals under the SPT for a limited number of years, meaning their US days do not count during that period. Many F-1 students in the US fewer than five years are non-residents filing Form 1040-NR.
• E-2 treaty investor visa holders often face complex situations involving business income, treaty benefits, and the interaction between investor status and tax residency, especially when also running a US entity.
• Green card holders are resident aliens for tax purposes worldwide, including years spent living mainly outside the US, unless they formally abandon the green card.

If your immigration situation is complex — pursuing an employment-based green card while on a work visa, for instance — keeping your tax filings clean and consistent is worth the effort, since tax records are sometimes requested during immigration adjudications.

If you are still in the planning stage, understanding the full cost of living in the US is useful groundwork. Our guide to Affordable Co-Living Spaces in the USA for New Residents is a practical starting point, and housing cost directly shapes how much of your income is left to cover tax obligations and savings.

State Income Tax Returns: The Second Filing Most Immigrants Forget

Most states with a personal income tax require their own return, filed with the state department of revenue or taxation. Rules on who must file, what income counts, which deductions apply and what credits exist differ substantially from federal rules and from state to state.

Some states, including Florida, Texas and Nevada, have no personal income tax at all. Others, including California, New York and Massachusetts, have significant state taxes and active enforcement.

If you moved between states during the year, you may owe tax in more than one and need part-year resident returns. If you worked remotely for a company based in a different state from where you lived, some states may assert a claim on that income. State tax adds meaningful complexity; raise it early with any tax professional.

For business owners, state obligations extend to entity-level filings and franchise taxes. The Annual Report & Franchise Tax by State: 2026 Guide covers those separate requirements.

When to Hire an International Tax CPA or IRS Enrolled Agent

A professional — ideally a Certified Public Accountant or IRS Enrolled Agent with cross-border experience — is worth engaging if any of the following apply:

• You are a non-resident alien or dual-status filer
• You have income from multiple countries
• You are claiming a tax treaty benefit
• You hold foreign financial accounts or assets above reporting thresholds
• You own or hold an interest in a foreign corporation or partnership
• You are self-employed with clients in more than one country
• You received a significant inheritance or gift from abroad
• You have unreported prior years that need to be brought into compliance

If professional fees are a concern, the IRS Volunteer Income Tax Assistance (VITA) programme offers free basic tax preparation for eligible filers, including many immigrants, and some VITA sites have preparers trained in non-resident returns. Check IRS.gov for a location near you.

Amended Returns: Fixing Errors with Form 1040-X

If you filed and later find an error — omitted income, an incorrect deduction, a missing form — file an amended return using Form 1040-X. You can generally amend for up to three years from the original filing date, or two years from when you paid the tax, whichever is later, to claim a refund. There is no deadline for amending if you owe more, but interest and penalties accrue from the original due date.

Non-resident alien returns also use Form 1040-X, noting the original form filed, though procedures can vary. If you are amending to claim a treaty benefit not originally claimed, specialist guidance is advisable.

How Long to Keep Tax Records After You File

The IRS generally has three years from the filing date to audit a return, six years if it suspects a substantial understatement of income (more than 25% of gross income omitted), and no statute of limitations where fraud is alleged or no return was filed. Different rules sometimes apply to foreign-related filings. Practically:

• Keep copies of all returns and supporting documents for at least seven years
• Retain cost basis records for investments indefinitely, since you need them when you sell
• Keep FBAR records for five years from the filing deadline
• Store copies securely, digitally and on paper, including copies you can access from outside the US if you travel or relocate

Pre-Submission Checklist

Before hitting submit, confirm you have:

• Determined your correct tax residency status (resident alien, non-resident alien, or dual-status)
• Confirmed you have a valid SSN or active ITIN
• Collected all income documents (W-2, 1099 series, 1042-S, foreign income records)
• Chosen the correct form (1040 or 1040-NR)
• Attached all required schedules and international forms (8938, 2555, 1116, 8833 as applicable)
• Applied the correct deduction method, standard or itemised
• Calculated self-employment tax if applicable (Schedule SE)
• Reviewed whether state returns are required
• Checked your FBAR obligation and filed separately if required
• Signed and dated your return
• Paid any balance due by the original deadline, even if filing on extension
• Saved copies of everything submitted

This article is general educational information. It is not tax advice, legal advice, or financial advice for your individual situation. Tax law is complex and changes frequently. Always verify figures, thresholds and deadlines against current IRS publications at IRS.gov. Consult a qualified CPA, enrolled agent or tax attorney for guidance specific to your circumstances, particularly if you have cross-border income, foreign accounts, or complex immigration status.

Frequently Asked Questions

Do I have to file a US tax return if I only lived in the US for part of the year?
It depends on your residency status and how much income you earned while present. Green card holders and citizens must report worldwide income for the entire year, even if they lived abroad for part of it. Non-resident aliens file only on US-source income. Dual-status filers, who changed status during the year, may need two returns or a special dual-status return. Consult a CPA who handles international filers.

Can I file a US tax return without a Social Security Number?
Yes. If you are not eligible for an SSN, apply for an Individual Taxpayer Identification Number using Form W-7. You enter the ITIN in the same field where an SSN would appear. Some treaty benefits and tax credits are restricted for ITIN holders, so read the IRS instructions carefully and consider professional guidance.

What is the difference between a resident alien and a non-resident alien for US tax purposes?
The IRS uses the Green Card Test and the Substantial Presence Test. Passing either makes you a resident alien, taxed on worldwide income like a US citizen. Failing both makes you a non-resident alien, taxed only on US-source and certain effectively connected income. Your visa type is relevant context but does not automatically determine tax status.

What happens if I miss the US tax filing deadline?
If you owe tax and file late without an extension, the IRS charges a failure-to-file penalty as a percentage of unpaid tax per month, plus a failure-to-pay penalty and interest. If you are due a refund and simply file late, there is generally no penalty, but refunds expire if you wait too long. File as soon as possible, and if you cannot pay in full, explore IRS payment plan options rather than not filing.

What forms do immigrants most commonly need to file a US return?
Resident aliens typically file Form 1040, the same form US citizens use. Non-resident aliens file Form 1040-NR. Additional schedules depend on income sources: Schedule B for interest and dividends, Schedule C for self-employment, Schedule D for capital gains. You may also need Form 8938 for foreign financial assets or FinCEN 114 for foreign bank accounts. A tax professional can confirm which apply.

Is income I earned in my home country before moving to the US taxable?
If you became a US resident alien during the year, the general rule is that worldwide income from the date you became a resident is taxable. Income earned before that date may or may not be taxable depending on the tax treaty between the US and your home country. Treaty rules are complex and must be analysed individually; a CPA experienced in international taxation is essential here.

Can I claim a tax treaty benefit on my US return?
Possibly. The US has income tax treaties with many countries that can reduce or eliminate tax on certain income types. To claim one, you generally disclose it on Form 8833 and report the income as treaty-exempt. Not all visa categories can claim all treaty benefits, and some treaties have residency tie-breaker rules. Never rely on a treaty claim without professional guidance.

What is FBAR and is it part of my tax return?
FBAR is the Report of Foreign Bank and Financial Accounts, FinCEN Form 114. It is not filed with your tax return; it is submitted separately through the FinCEN BSA E-Filing System. You must file it if the aggregate value of your foreign financial accounts exceeded the threshold at any point during the calendar year (check the current figure at fincen.gov). Penalties for non-filing can be severe, so treat it as seriously as the return itself.

Disclosure: This article is for general information only. It is not legal, immigration, tax, or financial advice. Rules, fees and eligibility criteria change frequently and vary by individual circumstance. Consult a qualified attorney or licensed professional before acting on anything you read here.