Filing a US tax return — forms and deadlines

Filing a federal income tax return in the United States is a legal requirement for residents, citizens, and visa holders meeting certain income thresholds. Understanding the different forms, who files them, and when they are due is essential for avoiding penalties and ensuring compliance with the Internal Revenue Service (IRS).

The main deadline

Federal tax returns for the previous calendar year are due by midnight on April 15 each year. For the 2024 tax year, returns were due on April 15, 2025. For the 2025 tax year, returns will be due on April 15, 2026. If April 15 falls on a weekend or a federal holiday, the deadline moves to the next business day. If you cannot file by the deadline, you can request an automatic extension, which gives you until October 15 to file—though this does not extend the deadline to pay any taxes you owe.

W-2 forms: employees and tax withholding

If you work as an employee (not self-employed), your employer is required to withhold taxes from every paycheck. At the end of the year, your employer provides you with a Form W-2, Wage and Tax Statement. This form summarizes your annual wages, tips, and compensation, as well as the amount of federal, state, and local taxes your employer already withheld on your behalf.

The employer sends W-2 forms to you by January 31 of the following year. Your employer also files a copy with the IRS. When you file your tax return, you report the income and withholdings from your W-2 on Form 1040, the basic U.S. individual income tax return form.

As a W-2 employee, you usually do not need to make quarterly tax payments during the year because your employer is already handling the withholding. However, if your total tax liability is significantly higher than what has been withheld—for example, because you have a second job or substantial side income—you may need to make estimated quarterly payments or adjust your withholding.

1099 forms: independent contractors and freelancers

If you work as an independent contractor, freelancer, or self-employed person, your clients or employers issue you a Form 1099 instead of a W-2. The most common form is the 1099-NEC (Nonemployee Compensation), which reports payments you received for services. You must receive a 1099-NEC if you were paid $600 or more in a calendar year. A second type, Form 1099-MISC, is used for certain miscellaneous payments such as rent or royalties.

The key difference from W-2 work is that nobody withholds taxes from 1099 payments. You are responsible for setting aside and paying all federal, state, and self-employment taxes yourself. No withholding happens automatically, which is why many new contractors are surprised at tax time to discover they owe more than expected.

Quarterly estimated tax payments

Because no withholding occurs with 1099 income, the IRS requires contractors and other self-employed individuals to make quarterly estimated tax payments throughout the year. These payments are due four times per year: April 15, June 16, September 15, and January 15. You must make quarterly payments if you expect to owe $1,000 or more in federal taxes for the year after accounting for any credits or withholding from other sources.

The purpose of quarterly payments is to spread the tax burden evenly across the year, just as withholding does for employees. If you wait until April 15 of the next year to pay all your taxes, you may owe penalties and interest. To calculate how much to pay each quarter, you use Form 1040-ES, Estimated Tax for Individuals, available on the IRS website.

• If you underpay estimated taxes, penalties start at 0.5% of the amount owed and increase monthly, up to 25% maximum.
• You can pay estimated taxes electronically through the IRS Electronic Federal Tax Payment System (EFTPS) or by mail using Form 1040-ES.
• If your income changes significantly during the year, you can recalculate and adjust future payments to avoid overpayment.

Form 1040: the individual income tax return

Form 1040 is the core U.S. federal income tax form. You use it to report all sources of income—from W-2 wages to 1099 contractor earnings to investment income—and to claim deductions, credits, and any payments you have already made during the year. Depending on your situation, you may also need to file additional schedules, such as Schedule C (for self-employment income) or Schedule 1 (for certain types of income and adjustments).

You file Form 1040 either on paper by mail or electronically (e-filing). Electronic filing is faster, more secure, and the IRS processes e-filed returns more quickly, often within 21 days if you choose direct deposit for any refund.

Free filing options for those with low to moderate income

You do not always need to hire a tax preparer or purchase commercial tax software. The IRS offers several free filing options to help you prepare and file your return yourself at no cost.

IRS Free File

The IRS Free File program is a public-private partnership through which leading tax software companies offer free online tax preparation software to eligible taxpayers. If your adjusted gross income (AGI) is $84,000 or less, you can use one of the participating software programs to prepare and file your federal return for free. Each provider sets its own eligibility requirements, so check individual program details on the IRS website.

VITA and Tax Counseling for the Elderly

The Volunteer Income Tax Assistance (VITA) program provides free in-person tax preparation from IRS-certified volunteers at community centers, libraries, schools, and other locations. You qualify if you earn $67,000 or less, have a disability, have limited English proficiency, or work with complex forms. Tax Counseling for the Elderly (TCE), operated largely through the AARP Foundation, offers similar services focused on taxpayers aged 60 and older, with special emphasis on retirement and pension issues.

To find a VITA or TCE site near you, visit the IRS website or call 1-800-906-9887 (VITA) or 1-888-227-7669 (AARP TCE). Virtual services are often available, and you can prepare returns online with a volunteer's guidance.

IRS Direct File

In eligible states, the IRS also offers IRS Direct File, a web-based service that allows you to file your federal return directly with the IRS for free. It provides guided preparation in English and Spanish and is available on smartphones, tablets, and computers. Check the IRS website to see if Direct File is available in your state.

State income tax returns

In addition to your federal return, you may be required to file a state income tax return. However, state tax rules, deadlines, and income thresholds vary significantly by state. Some states, such as Texas, Florida, and Wyoming, do not impose a state income tax at all. Others have different deadlines or require different forms. You must check the tax agency website for the state or states where you worked during the year. In most cases, state returns are due on the same date as your federal return, April 15, but always verify this.

Non-citizens and special tax identification

If you do not have a Social Security Number (SSN) and are not eligible to obtain one, you can apply for an Individual Taxpayer Identification Number (ITIN) from the IRS. An ITIN allows you to file a U.S. tax return and is valid for tax purposes even if you do not have immigration status. You apply for an ITIN using Form W-7 and must include your original or certified passport or birth certificate as proof of identity. Processing takes several weeks.

International students, visa holders, temporary workers, and undocumented residents who earn income in the United States are required to file a federal tax return if their income exceeds the annual threshold. Using your ITIN on your tax return does not affect your immigration status.

Common mistakes and what to avoid

• Waiting until April 14 to gather documents: Employers and payers send forms by January 31. Start collecting by early February to avoid last-minute stress.
• Assuming an extension to file is an extension to pay: It is not. If you file an extension but still owe taxes, interest and penalties accrue on any unpaid balance from April 15, even though you have until October 15 to file.
• Not setting aside money as a contractor: Set aside 25–30% of 1099 income in a separate savings account so you have cash available when quarterly or annual payments are due.
• Ignoring your state's specific requirements: Each state has different rules. Do not assume your state follows federal rules or deadlines.
• Failing to file if you had a loss or owe nothing: If you had a loss on Schedule C or owe no federal tax, you may still be required to file to preserve certain credits or to comply with state law.

Resources

The IRS website (irs.gov) is the authoritative source for all federal tax forms, instructions, and deadlines. You can download all forms and publications free of charge. The IRS also operates a taxpayer assistance telephone line at 1-800-829-1040 (English) and 1-800-829-1040 (Spanish, press 2). For immigrant-specific guidance, organizations like the American Immigrant Council and local legal aid societies offer free or low-cost help.