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

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 follows a logical sequence: determine whether you must file, gather your documents, choose the right form, calculate your tax, and submit on time. For immigrants and internationals, a few additional layers apply — your tax residency status, your taxpayer identification number, potential foreign account reporting, and treaty eligibility — and this guide covers all of them.

Why This Matters in 2026

Several developments make 2026 a particularly important year to get your US tax filing right.

The IRS has continued expanding its direct e-file infrastructure, meaning more filers can submit returns at no cost through official channels. At the same time, IRS enforcement around FATCA (the Foreign Account Tax Compliance Act) and FBAR reporting has intensified, with increased data-sharing agreements between the US and foreign financial institutions. If you hold accounts overseas — whether back home or in a third country — those accounts are increasingly visible to the IRS regardless of whether you disclose them.

For immigrants specifically, 2026 brings an added dimension: public charge rules and immigration benefit adjudications can sometimes touch on financial history, and an unfiled or incorrect tax return can complicate visa renewals, green card applications, and citizenship petitions in ways that go far beyond a simple penalty notice. If you are navigating an investor or employment visa alongside your tax situation, resources like Best CPAs for Foreign-Owned US Businesses in 2026: Tax Filing, FATCA, and ITIN Help can help you find specialist professional support.

Step 1: Determine Whether You Are Required to File

Before anything else, you need to know 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 IRS does not use your immigration visa category to decide how to tax you. Instead, it applies two tests:

• Green Card Test: If you held a lawful permanent resident card (green 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 in the US mid-year and crossed the SPT threshold, you may be a dual-status alien — a resident for part of the year and a non-resident for the rest. This is one of the more complex scenarios in US tax law. Seek a CPA who specialises in international filers.

Income Thresholds

The IRS sets minimum gross income levels below which a return is not required for most filers. These thresholds adjust each year and vary by filing status and age. Always verify the current threshold in IRS Publication 501 or the current year's Form 1040 instructions. That said, even if your income falls below the threshold, you may still want to file — particularly if tax was withheld from your wages and you are due a refund, or if you are eligible for refundable credits.

Step 2: Obtain Your Taxpayer Identification Number

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 who are not eligible for an SSN but have a US tax filing requirement — including non-resident aliens with US income, dependants claimed on a return, and others. For detailed guidance on the ITIN application process, see ITIN Application Process for Business Owners 2026.

Important: 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

Rushing into tax software without your documents in hand is one of the most common sources of errors. Spend time collecting the following:

Income Documents

• Form W-2: Wages from US employers (issued by your employer 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 who must report worldwide income)

Deduction and 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 financial accounts — needed for FBAR (FinCEN 114) and potentially Form 8938

Step 4: Choose the Right Tax 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 the schedules attached vary.

Non-resident aliens file Form 1040-NR. This form has different sections reflecting the different 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 a detailed walkthrough of that process.

Step 5: Calculate Your Taxable Income and Tax Owed

This is the arithmetic heart of your return. The sequence is:

1. Total Gross Income — Add up all income from all sources (worldwide, for resident aliens and citizens)
2. Above-the-Line Deductions — Subtract eligible adjustments (student loan interest, contributions to certain retirement accounts, self-employment tax deduction, etc.) to arrive at Adjusted Gross Income (AGI)
3. Standard Deduction or Itemised Deductions — Subtract whichever is larger. The standard deduction amount adjusts annually for inflation; verify the current figure in the Form 1040 instructions at IRS.gov. Most filers use the standard deduction. Note: non-resident aliens generally cannot claim the standard deduction 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 rate brackets to your taxable income. The IRS publishes the current brackets in Publication 17 and the Form 1040 instruction booklet.
6. Credits — Subtract eligible tax credits (child tax credit, education credits, foreign tax credit, etc.) from the tax calculated. Credits are more valuable than deductions because they reduce tax dollar-for-dollar.
7. Payments Already Made — Subtract withholding already paid (shown on your W-2 or 1099) and any estimated tax payments you made during the year
8. Refund or Amount Owed — The difference is either sent to you as a refund or must be paid by the deadline

Illustrative Example — Single Wage-Earner on 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 her 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 (applying illustrative bracket rates): ~$7,800
• Federal withholding already paid (W-2 Box 2): $8,500
• Refund: ~$700

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

Illustrative Example — Freelancer with Foreign 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 maintains 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: ~$5,150
• AGI: ~$67,850
• Standard deduction (illustrative): –$14,600
• Taxable income: ~$53,250
• Tax calculated: ~$7,200
• Self-employment tax (Schedule SE): ~$10,300
• Foreign tax credit (he paid local tax on the foreign income): –$2,100
• Total tax after credit: ~$15,400
• Estimated payments made during year: $12,000
• Amount owed at filing: ~$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: Complete and File Your Return

E-filing vs. Paper Filing

The IRS strongly prefers — and for most filers it is faster and more accurate to use — electronic filing. Options include:

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

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

If you owe tax, payment is due by the filing deadline even if you request an extension to file. Options include:

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

Step 7: File Foreign Account Reports (If Required)

This step sits outside your tax return but is closely linked to it.

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 (verify the current amount at fincen.gov) at any time during the year, you must file an FBAR. It is submitted through FinCEN's BSA E-Filing System — not through 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 — check IRS.gov for current figures), you attach Form 8938 to your tax return. FBAR and Form 8938 can overlap but are not substitutes for each other; you may need to file both.

Step 8: Handle Extensions and Deadlines

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 interest.

Common Mistakes Immigrants Make — and How to Avoid Them

1. Filing as a non-resident when you are actually a resident alien. Solution: 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. Solution: Resident aliens must report worldwide income. If you received a salary, freelance pay, rental income, or pension from outside the US, it belongs on your return even if you never transferred the money to a US account.

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

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

5. Using an expired or incorrect ITIN. Solution: ITINs that have not been used on a tax return for three consecutive years — or that were assigned before a certain year — expire. Renew using Form W-7 well in advance of the filing season.

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

7. Ignoring state tax obligations. Solution: Most US states with an income tax have their own filing requirement, separate from and in addition to the federal return. The rules for who must file vary by state. Check the revenue department website for any state where you lived or worked.

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

How Immigration Status Interacts with Tax Filing

Your visa category does not determine your tax residency (the SPT and Green Card Test do), but it provides important context:

• H-1B, L-1, 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 presence days do not count toward the SPT during that period. Many F-1 students who have been in the US fewer than five years are non-residents who file Form 1040-NR.
• E-2 treaty investor visa holders may have complex situations involving business income, treaty benefits, and the interaction between their investor status and tax residency — especially relevant if you're also managing a US entity.
• Green card holders are resident aliens for tax purposes worldwide, including years they live primarily outside the US, unless they formally abandon their green card.

If your immigration situation is complex — for example, you are pursuing an employment-based green card while on a work visa — it is worth ensuring your tax filings are clean and consistent, as tax records are sometimes requested during immigration adjudications.

For those still in the immigration planning stage, understanding the full financial picture of living in the US is valuable groundwork. Our guide to Affordable Co-Living Spaces in the USA for New Residents is a practical starting point for managing your cost of living, which in turn shapes how much of your income is available to cover tax obligations and savings.

State Tax Returns: Don't Forget the Second Filing

Most states with a personal income tax require their own return, filed with the state's department of revenue or taxation. The rules for who must file, what income is included, which deductions are allowed, and what credits are available differ substantially from federal rules — and from state to state. Some states (such as Florida, Texas, and Nevada) have no personal income tax at all; others (such as 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 multiple states and need to file part-year resident returns. If you worked remotely for a company in a different state from where you lived, some states may assert a tax claim on that income. State tax can add meaningful complexity; include it in your conversations with any tax professional.

For business owners, state-level obligations extend to entity-level filings and franchise taxes. The Annual Report & Franchise Tax by State: 2026 Guide is a useful companion resource for understanding those separate requirements.

When to Use a Tax Professional

A professional — ideally a Certified Public Accountant (CPA) or IRS Enrolled Agent with international 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 have foreign financial accounts or assets above reporting thresholds
• You own or have 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

The IRS's 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 site near you.

Amended Returns and Correcting Mistakes

If you filed a return and later discover an error — you forgot to include income, claimed a deduction incorrectly, or neglected to attach a required form — file an amended return using Form 1040-X. You can generally amend a return 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 additional tax, but interest and penalties accrue from the original due date.

For non-resident alien returns, use Form 1040-X as well (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.

Keeping 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 if fraud is alleged or no return was filed. For foreign-related filings, different rules sometimes apply. As a practical matter:

• Keep copies of all tax returns and supporting documents for at least seven years
• Retain records of the cost basis of investments indefinitely (you need them when you sell)
• Keep FBAR records for five years from the filing deadline
• Store copies securely — both digitally and in paper — and include copies accessible from outside the US in case you travel or relocate

Quick-Reference Checklist

Before hitting submit on your return, 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.