IRS forms
Form 1040: who must file, 2025 thresholds, due date, schedules and common errors
Form 1040 is the US individual income tax return. 2025 filing thresholds by status and age, the $400 self-employment rule, the April 15, 2026 due date and extensions, Schedules 1, 1-A, 2 and 3, the records to keep, penalties and the errors that get returns rejected.
Prepared by Aldro Accounting · Updated · Sources checked
The quick answer
Form 1040 is the annual US individual income tax return filed with the IRS. A 2025 return is due April 15, 2026 for calendar-year filers, or October 15, 2026 with an automatic extension. Whether you must file depends on gross income, filing status and age, and anyone with $400 or more of net self-employment earnings must file Form 1040 with Schedule SE.
What Form 1040 is
Form 1040 is used by US taxpayers to file an annual income tax return. Form 1040-SR is an optional alternative for taxpayers age 65 or older and uses the same schedules and instructions.
Business owners meet Form 1040 even when the business files its own return. A sole proprietor's Schedule C, a partner's or S corporation shareholder's share of income, and self-employment tax all end up on the owner's 1040.
Who must file a 2025 return
For a US citizen or resident, whether you must file depends on three things: gross income, filing status and age. The table shows the 2025 gross income thresholds.
You must also file Form 1040 and Schedule SE if net earnings from self-employment, excluding church employee income, were $400 or more, or church employee income was $108.28 or more. Other triggers include owing special taxes such as AMT, receiving HSA or MSA distributions, or having advance payments of the premium tax credit.
Due date and extensions
April 15, 2026 is the due date for a 2025 return if you use the calendar year. A fiscal-year return is due the 15th day of the 4th month after the year ends.
An automatic 6-month extension moves the filing date to October 15, 2026. It extends the time to file, not to pay. US citizens and residents living outside the US and Puerto Rico with their main place of business abroad, or on military duty abroad, get an automatic 2-month extension to June 15, 2026 without filing Form 4868. People serving in a combat zone get at least 180 days after leaving it.
Employers must send Form W-2 by February 2, 2026, and payers must send Forms 1099 by the same date, or February 17, 2026 for broker statements.
The numbered schedules
Business owners also attach lettered schedules, most often Schedule C for a sole proprietorship and Schedule SE for self-employment tax.
2025 standard deduction and the new Schedule 1-A deductions
The 2025 standard deduction is $15,750 for single or married filing separately, $31,500 for married filing jointly or qualifying surviving spouse, and $23,625 for head of household.
Schedule 1-A deductions can be claimed whether you take the standard deduction or itemize.
- Qualified tips: up to $25,000, limited when modified AGI is over $150,000 ($300,000 joint).
- Qualified overtime: up to $12,500 ($25,000 joint), with the same income limits.
- Passenger vehicle loan interest on a vehicle bought in 2025 for personal use: up to $10,000, limited over $100,000 ($200,000 joint).
- Enhanced senior deduction for people born before January 2, 1961: limited over $75,000 ($150,000 joint).
Records you need and how long to keep them
Keep receipts, canceled checks or other proof of payment and any records that support deductions or credits. The law doesn't require a special form of records.
Keep records that support the return for 3 years in most cases, 6 years if you leave out income that is more than 25% of the gross income shown, and with no limit if you file a fraudulent return or don't file. Keep property records until the limitation period ends for the year you dispose of the property.
Common Form 1040 errors
Mistakes found after filing are corrected on Form 1040-X. A refund claim on it is generally due within 3 years after filing the original return or 2 years after paying the tax, whichever is later.
- Name and SSN on the 1040, W-2 and 1099 don't match the Social Security card, which can reduce or disallow deductions and credits.
- Missing an SSN where required: $50 for each failure.
- Using a minus sign on a paper return. Put negative amounts in parentheses.
- No handwritten signature on a paper return. Digital, electronic or typed signatures aren't valid on paper.
- Leaving out an issued IP PIN on an e-filed return, which makes the signature invalid and the return rejected.
- Not answering the digital assets question on page 1.
Late filing and late payment penalties
The failure-to-file penalty is usually 5% of unpaid tax for each month or part of a month late, up to 25%. If the return is more than 60 days late, the minimum is the smaller of $525 or 100% of the unpaid tax. The failure-to-pay penalty is 0.5% a month, up to 25%. When both apply in a month, the failure-to-file penalty is reduced by the failure-to-pay penalty.
An accuracy-related penalty of 20% applies to underpayments from negligence or a substantial understatement, which is more than the larger of 10% of the correct tax or $5,000.
Aldro's flat yearly price includes the owner's personal return (1040) when it's needed for the business income, along with the business's federal and state returns. Our team prepares and files them.
Worked example
A single freelancer under 65 earned $12,000 of net self-employment income in 2025 and nothing else. That's below the $15,750 gross income threshold for single filers, but net self-employment earnings of $400 or more still require Form 1040 with Schedule SE. If she files on May 15, 2026 without an extension and owes $1,000, the failure-to-file penalty for that one partial month is 5%, reduced by the 0.5% failure-to-pay penalty, so $45 plus $5 for late payment.
Common questions
Who has to file Form 1040?
US citizens and residents whose gross income meets the threshold for their filing status and age, such as $15,750 for a single filer under 65 in 2025, and anyone with $400 or more of net self-employment earnings.
When is Form 1040 due?
April 15, 2026 for 2025 calendar-year returns, or October 15, 2026 with an automatic extension.
What's the difference between Form 1040 and 1040-SR?
Form 1040-SR is an optional version for taxpayers 65 or older. It uses the same schedules and instructions.
How long should I keep tax records?
Generally 3 years, 6 years if more than 25% of gross income was left off, and with no limit for a fraudulent or unfiled return.
How do I fix a mistake on my 1040?
File Form 1040-X. To claim a refund, file within 3 years of the original return or 2 years of paying the tax, whichever is later.
What's the penalty for filing a 1040 late?
Usually 5% of unpaid tax per month, up to 25%, with a minimum of the smaller of $525 or the unpaid tax if more than 60 days late.
The cheapest way to get your business taxes done: $399 flat.
Business tax filing is $399 USD a year, and it covers everything tax for that year.
How it works
- Tell us about your business. A two-minute form. No payment is collected through it.
- Get your next steps by email. We’ll email you the next steps within one business day. After you sign up we’ll send you a secure upload link for your documents.
- We file it. Our team prepares and files your return. Add bookkeeping for $20 a month if you want it.
What's included
$399 a year covers everything tax for that tax year.
- Every business return for the year. All the federal and state or provincial business returns you need for the tax year: Schedule C, 1065, 1120-S, 1120 and their state returns in the US; T2, or T1 with T2125, in Canada.
- More than one state. Multi-state returns are included at the same price.
- Your personal return. The owner’s personal return (1040 or T1) is included when it’s needed for the business income.
- Quebec. Quebec returns (CO-17, TP-1 and TP-80) are included. Our Quebec pages are in French, and our team works with you in English.
- Extensions and reminders. Extensions (Form 7004 or 4868) and quarterly estimate reminders are included.
- Information returns. 1099-NEC, T4/T4A and T5018 slips are included in the tax price.
- City and excise returns. City and local business tax returns, and state excise returns such as Washington B&O, are included in the yearly price.
- Franchise tax reports. State franchise tax reports, such as the Texas franchise tax report, are included.
- Estimated tax and instalment amounts. We work out your quarterly estimated tax payments in the US, or your CRA instalments in Canada, and tell you what to pay and when.
- Unfiled past years. Each unfiled prior-year return is $399 per tax year, the same flat price.
- Bookkeeping at $20 a month. Unlimited bank and card accounts, monthly reconciliation and monthly statements.
Basic inventory tracking for online stores, such as Shopify, is included. Full cost-of-goods reconciliation is quoted separately. Payroll processing and sales-tax filing aren’t included in bookkeeping. Prices are in USD. Our team prepares and files your return.
Sources
- IRS: About Form 1040 · checked October 31, 2026
- IRS: Publication 17 · checked October 31, 2026
This guide explains general rules from the sources listed. It isn’t tax advice for your situation.