IRS Form 1040 is the standard federal income tax return that individuals use each year to report income, claim deductions and credits, and settle up with the government on what they owe or are owed back. Most working adults file one. For the 2026 tax year, you generally must file if your gross income reaches $16,100 as a single filer under 65 or $32,200 as a married couple filing jointly where both spouses are under 65, though several other situations require a return regardless of income.
Who Has to File
Federal law ties the filing requirement to gross income, filing status, and age.1Office of the Law Revision Counsel. 26 USC 6012 – Persons Required to Make Returns of Income The thresholds match the standard deduction and change each year with inflation. For 2026:2Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
- Single filers under 65: $16,100
- Married filing jointly, both under 65: $32,200
- Head of household, under 65: $24,150
Age raises the floor. The additional standard deduction for 2026 is $2,050 for unmarried filers and $1,650 per qualifying spouse for married filers.3IRS.gov. Revenue Procedure 2025-32 – Inflation-Adjusted Items for 2026 A single filer who is 65 or older does not need to file unless gross income exceeds $18,150. A married couple filing jointly where both spouses are 65 or older does not need to file until gross income exceeds $35,500.
Some situations require you to file no matter how little you earned. Net self-employment income over $400 triggers self-employment tax and a required return.4Internal Revenue Service. Check if You Need to File a Tax Return Receiving advance payments of the premium tax credit for marketplace health insurance also requires filing, even if your income is otherwise below the threshold.5Internal Revenue Service. Premium Tax Credit (PTC) Overview
Filing Rules for Dependents
Being claimed as someone’s dependent doesn’t automatically excuse you from filing your own return. A dependent generally must file once gross income exceeds the larger of $1,350 or earned income plus $450, up to the full standard deduction amount.6Internal Revenue Service. Publication 501 – Dependents, Standard Deduction, and Filing Information A teenager with a modest part-time job usually doesn’t need to file. A child with meaningful investment income may need to file with much less coming in.
Children with unearned income above $1,350 for 2026 may owe what’s commonly called the “kiddie tax,” which taxes a portion of that income at the parent’s rate.3IRS.gov. Revenue Procedure 2025-32 – Inflation-Adjusted Items for 2026 Parents can sometimes fold a child’s income into their own return, but only when the child’s gross income falls between $1,350 and $13,500 and consists entirely of interest and dividends.
When Filing Is Optional but Smart
Even below the threshold, filing is often worth the effort. The IRS points to three common reasons to file voluntarily: federal income tax was withheld from your pay, you made estimated tax payments during the year, or you qualify for a refundable credit like the Earned Income Tax Credit or Child Tax Credit.4Internal Revenue Service. Check if You Need to File a Tax Return Skip the return and you forfeit any refund; you generally have three years from the original due date to claim it.
What to Gather Before You Start
Everyone listed on the return, including your spouse and any dependents, needs a valid Social Security number or Individual Taxpayer Identification Number.7Internal Revenue Service. Taxpayer Identification Numbers (TIN) A wrong number can delay a refund or generate an IRS notice.
Wage earners receive Form W-2 from each employer by January 31.8Social Security Administration. Deadline Dates to File W-2s Freelancers and independent contractors receive Form 1099-NEC from businesses that paid them.9Internal Revenue Service. About Form 1099-NEC, Nonemployee Compensation Dividend income comes on Form 1099-DIV, which financial institutions send to you and the IRS.10Internal Revenue Service. About Form 1099-DIV, Dividends and Distributions
Form 1040 now includes a mandatory yes-or-no question about digital assets. If you received, sold, exchanged, or otherwise disposed of any digital asset, including cryptocurrency, you must answer “Yes” and report the transactions, whether or not they produced a gain.11Internal Revenue Service. Digital Assets
If you plan to itemize instead of taking the standard deduction, pull together records of mortgage interest, charitable contributions, state and local taxes paid, and other qualifying expenses. Keep receipts and statements in case the IRS asks later.
Schedules That Attach to Form 1040
The two-page Form 1040 is a summary. When your situation is more complicated, you attach schedules that show the detail behind the numbers.
Schedule A for Itemized Deductions
Itemizing on Schedule A can lower your tax bill if your qualifying expenses exceed the standard deduction. Deductible items include medical and dental expenses above 7.5 percent of adjusted gross income, home mortgage interest, state and local taxes up to $10,000, and charitable contributions.12IRS.gov. Instructions for Schedule A (Form 1040)
Schedule B for Interest and Dividends
Receive more than $1,500 in taxable interest or ordinary dividends and you must attach Schedule B listing each payer and amount.13Internal Revenue Service. About Schedule B (Form 1040), Interest and Ordinary Dividends Schedule B also requires disclosure of a financial interest in a foreign bank account.
Schedule C for Business Profit or Loss
Sole proprietors and freelancers use Schedule C to report business income and deduct ordinary expenses such as advertising, office supplies, and professional fees.14Internal Revenue Service. About Schedule C (Form 1040), Profit or Loss from Business (Sole Proprietorship) Net profit flows onto Form 1040 and feeds Schedule SE.
Schedule SE for Self-Employment Tax
Net self-employment earnings of $400 or more require Schedule SE, which figures your Social Security and Medicare taxes. The combined rate is 15.3 percent: 12.4 percent for Social Security on earnings up to $184,500 in 2026, plus 2.9 percent for Medicare on all net earnings.15Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes)16Social Security Administration. Contribution and Benefit Base An additional 0.9 percent Medicare surtax kicks in once self-employment income combined with any wages exceeds $200,000 for single filers or $250,000 for married couples filing jointly.
How and When to File
Most taxpayers file electronically, which processes faster and confirms receipt right away. IRS Free File offers guided tax software at no cost to taxpayers with adjusted gross income of $89,000 or less, and Free File Fillable Forms are available at any income level for those comfortable preparing their own return.17Internal Revenue Service. E-file: Do Your Taxes for Free Start at IRS.gov/freefile; going directly to a partner’s commercial site won’t give you the free version. Commercial software and paid preparers are also available, with professional preparation fees for a basic return typically running $200 to $600.
Paper filing is still allowed. Mailed returns go to a specific IRS processing center based on your state and whether you’re enclosing payment.18Internal Revenue Service. Where to File Addresses for Taxpayers and Tax Professionals Filing Form 1040 or Form 1040-SR Paper takes considerably longer to process. E-file with direct deposit and the IRS typically issues refunds in fewer than 21 days.19Internal Revenue Service. Why It May Take Longer Than 21 Days for Some Taxpayers to Receive Their Federal Refund
The filing deadline is April 15. If that date falls on a weekend or legal holiday, it shifts to the next business day.20Internal Revenue Service. When to File Need more time? File Form 4868 before April 15 and you get an automatic six-month extension to October 15.21Internal Revenue Service. Get an Extension to File Your Tax Return The extension covers filing, not payment. You still owe your taxes by April 15, and interest accrues on anything unpaid after that date.
Paying What You Owe
A balance due can be paid several ways. IRS Direct Pay moves money from a checking or savings account at no charge and lets you schedule payments up to 365 days ahead. The Electronic Federal Tax Payment System (EFTPS) handles the same job for larger or more frequent payments but requires enrollment. Credit card, debit card, and digital wallet payments run through third-party processors that charge a fee.22Internal Revenue Service. IRS Payment Options
If you earn income that isn’t subject to withholding, such as self-employment, investment, or rental income, you generally need to make quarterly estimated tax payments. To avoid an underpayment penalty, total payments (withholding plus estimated) should cover either 90 percent of your current-year tax or 100 percent of your prior-year tax, whichever is less. If your prior-year adjusted gross income exceeded $150,000 ($75,000 for married filing separately), the prior-year safe harbor rises to 110 percent.23Internal Revenue Service. Estimated Tax
Penalties and Interest
Missing the filing deadline hurts. The failure-to-file penalty is 5 percent of unpaid tax for each month or partial month the return is late, capped at 25 percent. If the return is more than 60 days late, the minimum penalty is $525 or 100 percent of unpaid tax, whichever is less.24Internal Revenue Service. Failure to File Penalty
A separate failure-to-pay penalty applies when you file on time but don’t pay the balance. It runs 0.5 percent of unpaid tax per month, also capped at 25 percent.25Internal Revenue Service. Failure to Pay Penalty When both penalties apply in the same month, the failure-to-file penalty is reduced by the failure-to-pay amount, so you’re not paying both in full at once. An approved payment plan cuts the failure-to-pay rate to 0.25 percent per month.
Interest accrues on unpaid balances on top of penalties. As of the first quarter of 2026, the IRS charges 7 percent annual interest on underpayments.26Internal Revenue Service. Quarterly Interest Rates The rate is set quarterly and compounds daily.
Fixing a Mistake with Form 1040-X
Spot an error after filing? Unreported income, a missed deduction, the wrong filing status? Correct it with Form 1040-X, the amended return. You can now e-file Form 1040-X for the current tax year and the two prior tax years, and paper filing is still available.27Internal Revenue Service. About Form 1040-X, Amended U.S. Individual Income Tax Return
To claim a refund from an amendment, you generally must file within three years of the date the original return was filed or two years after the tax was paid, whichever is later. Filing early doesn’t start the clock sooner; the IRS counts from the April deadline even if you filed in February.28Internal Revenue Service. File an Amended Return Extended deadlines apply in situations like federally declared disasters, service in a combat zone, or claims tied to bad debt or worthless securities.
State Returns Are Separate
Filing your federal Form 1040 doesn’t handle your state taxes. Most states impose an individual income tax and require a separate state return with its own rules and deadline. Information from your federal return, especially adjusted gross income and federal tax paid, often carries over as the starting point for the state return. Check your state’s tax agency for the specifics that apply to you.