To file Form 1040 for the 2025 tax year, gather your income documents, pick a filing status, complete the form (on paper or, more commonly, through tax software), and submit it to the IRS by April 15, 2026. Most filers e-file and receive any refund by direct deposit within three weeks. The steps below walk through what to collect, how the form flows, how to send it in, and what to do if something goes wrong.
Before You Start: What to Gather
Pulling everything together first saves you from stopping halfway through to hunt for a missing form. You’ll need:
- Social Security numbers or ITINs for you, your spouse, and every dependent you plan to claim. The names on the return must match Social Security Administration records, so if you changed your name recently, update it with SSA before filing.1Internal Revenue Service. Gather Your Documents
- Every W-2 from every employer you worked for in 2025. Employers must send them by the end of January.2Internal Revenue Service. About Form W-2, Wage and Tax Statement
- Any 1099s you received: 1099-INT for bank interest, 1099-DIV for dividends, 1099-NEC for freelance or contract work, 1099-R for retirement distributions. Income counts even if no form arrived for it.
- Records for deductions and credits: mortgage interest statements, property tax and state income tax payments, charitable donation receipts, medical expenses, student loan interest, IRA contributions, educator expenses.
- Bank routing and account numbers if you want a direct-deposit refund or plan to pay a balance electronically.
One filing-status note before you dig in. A qualifying child generally must be under 19 (or under 24 if a full-time student), live with you more than half the year, and get more than half their support from you. A qualifying relative must have gross income under $5,050 for 2025 and depend on you for more than half their support. Either way, the person has to be a U.S. citizen, U.S. resident, or a resident of Canada or Mexico, and can’t be claimed on anyone else’s return.3Internal Revenue Service. Dependents
A quick check on whether you need to file at all: for a single filer under 65, the threshold is $15,750 in gross income for 2025, and the thresholds for other statuses track the standard deduction. Self-employment income of $400 or more requires a return no matter what your total income is, and anyone who received advance premium tax credit payments through a health insurance marketplace has to file to reconcile them.4Internal Revenue Service. Check if You Need to File a Tax Return5Office of the Law Revision Counsel. 26 USC 6017 – Self-Employment Tax Returns6Internal Revenue Service. Premium Tax Credit (PTC) Overview Even below the threshold, filing is worth it if federal tax was withheld from your paycheck, because a return is how you get that money back.
Filling Out Form 1040
The form itself is two pages. Schedules 1 through 3 handle anything that doesn’t fit on those pages. Work through it in this order.
1. Choose Your Filing Status
Your status controls your tax brackets and standard deduction. For 2025 the standard deduction is $15,750 for single filers and married filing separately, $31,500 for married filing jointly and qualifying surviving spouses, and $23,625 for heads of household.7Internal Revenue Service. New and Enhanced Deductions for Individuals Compare that number to what you’d get by itemizing; whichever is bigger is what you claim.
2. Enter Personal Information
Names, addresses, and Social Security numbers for you, your spouse, and each dependent. If any of that is wrong, the IRS will reject the return.
3. Report Your Income
Transfer the wage figure from your W-2s onto the wages line. Add interest, dividends, capital gains, retirement distributions, and any other income from your 1099s to the corresponding lines. Federal law defines gross income broadly to include compensation, business earnings, rents, royalties, and essentially any economic gain during the year.8Office of the Law Revision Counsel. 26 USC 61 – Gross Income Defined
4. Calculate Adjusted Gross Income
Subtract above-the-line adjustments (student loan interest, educator expenses, traditional IRA contributions, and other items reported on Schedule 1) from total income. The result is your adjusted gross income.9Office of the Law Revision Counsel. 26 USC 62 – Adjusted Gross Income Defined AGI matters beyond your tax bill because it determines eligibility for many credits and deductions.
5. Subtract Deductions and Apply Tax
Subtract either the standard deduction or your itemized deductions from AGI to get taxable income. Look up the tax on that amount using the tax tables or brackets. Then reduce that tax dollar-for-dollar by any credits you qualify for, such as the child tax credit or earned income tax credit.
6. Compare to What You Already Paid
Add up federal income tax withheld from your W-2s and 1099s and any estimated payments you made during the year. If that total exceeds your tax, the difference is your refund. If it falls short, you owe the balance.
How to Submit the Return
Free File and Paid Software
E-filing is faster and more accurate than paper. If your AGI is $89,000 or less, IRS Free File lets you use brand-name tax software at no cost through eight private-sector partners participating for the 2026 filing season.10Internal Revenue Service. Use IRS Free File to Conveniently File Your Return at No Cost Above that limit, you can use Free File Fillable Forms (electronic forms with no guided preparation) or buy commercial software. The IRS acknowledges e-filed returns within 24 to 48 hours and flags basic errors immediately so you can fix and resend.
Paper
You can still print Form 1040 from IRS.gov, fill it out by hand, sign it, and mail it to the processing center for your region. Use the form version that matches the tax year you’re reporting. Paper returns take six weeks or more to process, and refund tracking doesn’t start until about four weeks after the IRS receives your envelope.11Internal Revenue Service. Refunds
Hiring a Preparer
A CPA or enrolled agent is worth the money if your situation is complicated: rental properties, self-employment, stock option exercises, or multistate filing. A standard Form 1040 with itemized deductions typically runs $300 to $600 nationally, with higher fees in major metro areas and for more complex returns. Most preparers can e-file for you.
State Returns Are Separate
Filing federal Form 1040 does not satisfy state income tax. Most states with an income tax require their own return, usually starting from the federal AGI on your 1040. Tax software typically prepares and transmits both together, but the state return has its own deadline and rules.
If You Can’t Finish by April 15
File Form 4868 to get an automatic six-month extension, pushing the filing deadline to October 15, 2026. No reason required; the extension is automatic as long as the form arrives on time.12Internal Revenue Service. Form 4868 Application for Automatic Extension of Time to File U.S. Individual Income Tax Return
The catch trips people up every year. An extension to file is not an extension to pay. Any tax you owe is still due April 15, and interest and penalties start accruing on unpaid balances after that date even with an approved extension.13Internal Revenue Service. Taxpayers Should Know That an Extension to File Is Not an Extension to Pay Taxes If you expect to owe, estimate the amount and send it with the extension request. U.S. citizens and residents living abroad on April 15 get an automatic two-month extension to June 15 without filing anything, though interest still runs from the original due date.
Getting Your Refund or Paying What You Owe
Direct deposit is the fastest route to a refund. The IRS issues more than nine out of ten refunds in fewer than 21 days when you e-file and choose direct deposit, and you can split the money across up to three accounts.14Internal Revenue Service. Get Your Refund Faster: Tell IRS to Direct Deposit Your Refund to One, Two, or Three Accounts Track it with the IRS “Where’s My Refund?” tool using your SSN or ITIN, filing status, and the exact refund amount from your return.15Internal Revenue Service. About Where’s My Refund?
If you owe a balance, pay by April 15, 2026 through one of these methods:16Internal Revenue Service. When to File
- IRS Direct Pay: free electronic transfer from a checking or savings account, with a $10 million per-payment cap.17Internal Revenue Service. Direct Pay With Bank Account
- EFTPS: a free Treasury system that handles larger payments and lets you schedule them in advance.18Internal Revenue Service. EFTPS: The Electronic Federal Tax Payment System
- Credit or debit card through a third-party processor, which charges a convenience fee.
- Check or money order mailed with Form 1040-V to the address in the form instructions.
Fixing a Mistake After You File
If you spot an error after filing (wrong status, unreported income, a missed deduction), correct it with Form 1040-X. You don’t need to amend for simple math errors or missing schedules; the IRS fixes those during processing.19Internal Revenue Service. File an Amended Return
To claim a refund on an amended return, you generally have three years from the date you filed the original return, or two years from the date you paid the tax, whichever is later.20Internal Revenue Service. Instructions for Form 1040-X Miss that window and the refund is gone. Most tax software can e-file Form 1040-X for the current year and the two prior years.
Penalties for Missing the Deadline
Missing April 15 triggers two separate penalties.
The failure-to-file penalty is 5% of unpaid tax for each month (or partial month) the return is late, capped at 25%.21Office of the Law Revision Counsel. 26 USC 6651 – Failure to File Tax Return or to Pay Tax For returns due after December 31, 2025, the minimum penalty is $525.22Internal Revenue Service. Failure to File Penalty This is the more expensive penalty of the two, so if you can’t pay, file on time anyway and deal with the balance separately.
The failure-to-pay penalty is 0.5% of unpaid tax per month, also capped at 25%. When both apply in the same month, the failure-to-file penalty is reduced by the failure-to-pay amount so you’re not double-charged. Setting up an IRS-approved payment plan drops the failure-to-pay rate to 0.25% per month.23Internal Revenue Service. Failure to Pay Penalty
Interest also runs on any unpaid balance. The rate for individual underpayments is 7% per year, compounded daily, and it applies to penalties as well as to the underlying tax.24Internal Revenue Service. Interest Rates Remain the Same for the First Quarter of 2026
Keep Your Records for at Least Three Years
Hold onto copies of the filed return and the documents behind it (W-2s, 1099s, receipts for deductions) for at least three years from the date you filed. That’s the standard statute of limitations for an IRS audit.25Internal Revenue Service. How Long Should I Keep Records Keep records six years if you underreported income by more than 25% of gross income, and indefinitely for any year you never filed at all.