Filing期限

Detailed explanation of Filing期限 based on official information from IRS・各州税務局. Accounting Processes

Published: January 12, 2026

Filing Federal Income Tax Returns in the United States

1. Overview

Filing a federal income tax return is a fundamental annual obligation for most individuals and entities earning income in the United States. It is the process by which taxpayers report their income, calculate their tax liability, claim deductions and credits, and either pay taxes owed or request a refund for overpayment. The Internal Revenue Service (IRS), the nation's tax administration agency, uses these returns to ensure compliance with the Internal Revenue Code. Timely and accurate filing is critical for avoiding penalties, securing refunds, and maintaining good standing with the federal government. The process also supports the functioning of federal programs funded by tax revenue.

2. Applicable Objects & Scenarios

Filing a federal tax return is generally required for:

  • Individuals: U.S. citizens and resident aliens whose gross income exceeds certain thresholds based on filing status (e.g., Single, Married Filing Jointly, Head of Household) and age. Even those below the threshold may need to file to claim a refund of taxes withheld or to qualify for refundable tax credits.
  • Business Entities: This includes sole proprietors (filing Schedule C), partnerships (filing Form 1065), corporations (filing Form 1120 or 1120-S), and S-corporations.
  • Estates and Trusts: Certain estates and trusts are required to file Form 1041.
  • Specific Scenarios: You must file if you owe specific taxes like alternative minimum tax, additional taxes on IRAs or other tax-favored accounts, or if you received advance payments of the Premium Tax Credit. Self-employed individuals with net earnings of $400 or more must also file.

3. Core Conclusions

  • Annual Requirement: For most taxpayers, the filing deadline is April 15 of the year following the tax year, unless an extension is filed.
  • Multiple Filing Methods: Taxpayers can file electronically (e-file) or by paper mail. The IRS strongly encourages e-filing for faster processing, greater accuracy, and quicker refunds.
  • Documentation is Key: Accurate filing depends on gathering all necessary income documents (like Forms W-2 and 1099) and records of deductions and credits.
  • Payments & Refunds: Filing a return determines if you have a balance due to the IRS or are due a refund. Payments can be made via various methods.
  • Extensions Available: An automatic extension to file (until October 15) can be requested, but it is not an extension to pay any tax owed.

4. Procedures & Steps

Step 1: Preparation

  1. Determine Your Filing Requirement: Check the IRS filing requirements based on your income, age, and filing status.
  2. Gather Documents: Collect all necessary forms:
    • Income Documents: W-2s from employers, 1099s for miscellaneous income (e.g., freelance, interest, dividends), and records of other income.
    • Deduction & Credit Records: Receipts for charitable contributions, mortgage interest statements (Form 1098), records of medical expenses, education expenses, and documentation for credits like the Child Tax Credit or Earned Income Tax Credit.
    • Prior Year Return: Your previous year's tax return can be a helpful reference.
  3. Choose Your Filing Method: Decide whether to file electronically using IRS Free File, commercial tax software, a tax professional, or by paper.
  4. Select Your Filing Status: Determine the correct status (e.g., Single, Married Filing Jointly).

Step 2: Application & Submission

  1. Complete the Tax Return:
    • Form Selection: Most individuals use Form 1040 (U.S. Individual Income Tax Return). Supplemental schedules (e.g., Schedule A for itemized deductions, Schedule C for business income) are attached as needed.
    • Report Income: Enter all income from your documents onto the appropriate lines and schedules.
    • Claim Deductions & Credits: Choose between the standard deduction or itemizing deductions. Apply for any tax credits you are eligible for.
    • Calculate Tax Liability: The form will guide you in calculating your total tax, credits, payments already made (via withholding), and the final balance (owed or refund).
  2. Submit the Return:
    • E-filing: Follow the instructions of your chosen software or tax preparer. You will receive an electronic acknowledgment upon acceptance by the IRS.
    • Paper Filing: Mail your completed return to the appropriate IRS address listed in the form's instructions. Use certified mail for proof of mailing.

Step 3: Review & Confirmation

  1. Review for Accuracy: Double-check all Social Security Numbers, math calculations, and bank account details for direct deposit of refunds.
  2. Make a Payment (if owed): If you have a balance due, arrange payment by the filing deadline to avoid penalties and interest. Options include direct pay, electronic funds withdrawal, credit/debit card, or check.
  3. File an Extension (if needed): To request an automatic 6-month extension to file, submit Form 4868 by the original due date. Remember, this does not extend the time to pay any tax due.
  4. Track Your Return: For e-filers, use the "Where's My Refund?" tool on IRS.gov or the IRS2Go app. For paper filers, allow 6-8 weeks for processing before checking status.

5. Frequently Asked Questions (FAQ)

Q1: What is the deadline to file my federal tax return? A1: For most individuals, the deadline is April 15. If April 15 falls on a weekend or holiday, the deadline moves to the next business day. You can request an automatic extension to file until October 15, but any tax owed is still due by the original April deadline.

Q2: What happens if I file my tax return late? A2: If you owe tax and file late, the IRS will assess a "Failure to File" penalty. This penalty is typically 5% of the unpaid taxes for each month or part of a month the return is late, up to 25%. Interest also accrues on unpaid penalties and taxes.

Q3: Can I file my federal tax return for free? A3: Yes. The IRS Free File program offers free guided tax preparation software to taxpayers whose adjusted gross income is below a certain threshold (please verify with official sources). For those above the threshold, Free File Fillable Forms are available.

Q4: How long should I keep my tax records? A4: The IRS generally recommends keeping records that support items on your tax return for at least three years from the date you filed the original return. In some cases, such as if you underreported income, you should keep records longer.

Q5: What is the difference between a tax deduction and a tax credit? A5: A deduction reduces the amount of your income that is subject to tax. A credit directly reduces the amount of tax you owe, dollar-for-dollar. Refundable credits can even result in a refund larger than the tax you paid.

Q6: How do I know if I can claim a dependent? A6: To claim someone as a dependent, they must meet specific tests for relationship, age, residency, support, and joint return filing. The IRS provides detailed guidelines in the Instructions for Form 1040.

Q7: What should I do if I made a mistake on my already-filed return? A7: If you discover an error, you may need to file an amended return using Form 1040-X. This form is used to correct previously filed Forms 1040, 1040-SR, or 1040-NR.

6. Risks & Compliance

  • Accuracy is Paramount: Providing incorrect information, whether intentional or not, can lead to audits, penalties, interest charges, and delays in refund processing.
  • Report All Income: You must report income from all sources, including side jobs, cash payments, and foreign accounts. Failure to do so can result in severe penalties.
  • Timely Payment: To avoid penalties and interest, any tax owed must be paid by the filing deadline, even if you request an extension to file.
  • Protect Your Information: Be vigilant against tax-related identity theft. Only provide your Social Security Number and tax information to trusted entities and secure your tax documents.
  • Disclaimer: This article provides general guidance. Tax situations are complex and can vary significantly. For advice specific to your circumstances, consult a qualified tax professional or refer directly to official IRS publications.

7. References & Sources

8. Related Topics

  • Tax Withholding (Form W-4)
  • Estimated Tax Payments
  • Tax Deductions: Standard vs. Itemized
  • Common Tax Credits (EITC, Child Tax Credit)
  • Amending a Tax Return (Form 1040-X)
  • IRS Audits and Examinations
  • State Income Tax Filing
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