U.S. Income Tax Filing Guide – Including All Key IRS Forms

Income tax is the most common tax in the U.S. and applies to both individuals and business entities. It is collected by the IRS (Internal Revenue Service) at the federal level, and in many cases, by state and local governments as well.

✅ What is US Income Tax?

US Income tax is a tax on money earned from:

Wages and salaries
Business income
Interest and dividends
Capital gains
Rental income
Royalties
Foreign income

The U.S. tax system is progressive, meaning higher income is taxed at higher rates (ranging from 10% to 37% for individuals in 2025).

✅ Types of Taxpayers

Taxpayer Type	Tax Form Used
Individuals	Form 1040
Corporations (C-Corp)	Form 1120
S-Corporations	Form 1120-S
Partnerships	Form 1065
Sole Proprietors	Schedule C (filed with 1040)
LLCs	Depends on election (1040/1065/1120)

✅ Key Income Tax Forms – Explained

🧾 For Individuals:

Form Number	Purpose	Who Uses It
Form 1040	U.S. Individual Income Tax Return	Every Individual Taxpayer
Schedule A	Itemized Deductions	For claiming deductions (mortgage, medical, etc.)
Schedule B	Interest and Dividend Income	If you earn interest or dividends over $1,500
Schedule C	Business Income (Sole Proprietors)	Self-employed, freelancers
Schedule D	Capital Gains and Losses	For sale of stocks, real estate, etc.
Schedule E	Rental and Royalty Income	Landlords, royalties, partnerships
Schedule SE	Self-Employment Tax	For Social Security/Medicare on business income
Form 1099 Series	Reports of various income (non- wage)	Freelancers, contractors, investment income
Form W-2	Wage and Tax Statement	Employees (provided by employer)
Form 8862	Reclaiming EITC after disallowance	For Earned Income Tax Credit cases
Form 2441	Child and Dependent Care Expenses	To claim credit for care expenses
Form 2555	Foreign Earned Income Exclusion	For U.S. citizens working abroad
Form 1116	Foreign Tax Credit	To claim credits for foreign taxes paid
Form 8962	Premium Tax Credit (Health Insurance)	For marketplace health coverage

🧾 For Businesses:

Form Number	Purpose	Who Uses It
Form 1120	U.S. Corporation Income Tax Return	C-Corporations
Form 1120-S	U.S. Income Tax Return for S- Corps	S-Corporations
Form 1065	U.S. Return of Partnership Income	Partnerships and some LLCs
Schedule K-1 (Form 1065)	Partner's Share of Income	Partners in partnerships
Schedule K-1 (Form 1120-S)	Shareholder's Share of Income	S-Corp shareholders
Form 941	Employer's Quarterly Tax Return	For reporting payroll taxes
Form 940	Annual Federal Unemployment (FUTA)	Employers
Form 1099-NEC	Nonemployee Compensation	For payments to contractors
Form 1099-MISC	Miscellaneous Income	Rents, prizes,etc.

✅ Due Dates

Form	Due Date
Form 1040 (Individual)	April 15 (Oct 15 with extension)
Form 1120 (C-Corp)	April 15 (for calendar year filers)
Form 1120-S & 1065	March 15 (for calendar year filers)

✅ Penalties for Non-Compliance

Late Filing Penalty: 5% per month up to 25%.
Late Payment Penalty: 0.5% per month up to 25%.
Accuracy-Related Penalty: 20% of underpaid tax.
Failure to File Foreign Forms (like FBAR, 8938): $10,000+ per form.

✅ Tax Filing Methods

E-filing: Fast, secure, and preferred by the IRS.
Paper filing: Still allowed but slower.
Use software like TurboTax, H&R Block, or hire a CPA or EA (Enrolled Agent).

✅ Conclusion

Getting a handle on U.S. income tax forms isn’t just paperwork—it’s the key to: