A tax is money the government collects from individuals and businesses to pay for public services
When you work, earn money, or buy something, you may owe a tax on that income or purchase. The federal government, your state, and your city or county all collect taxes. The money funds roads, schools, military defense, Social Security, Medicare, and thousands of other programs. The amount you owe depends on how much you earned, what type of income it was, and where you live.
Most people encounter taxes through their paycheck — your employer withholds a portion before you receive it — or when they file a tax return at the end of the year. If too much was withheld, you get a refund. If too little was withheld, you owe money. The Internal Revenue Service (IRS) is the federal agency that collects income taxes and enforces tax law.
Key Takeaways
- Income tax is the most common tax you pay, taken from wages, self-employment earnings, investments, and other sources.
- The amount of tax you owe is based on your income level and filing status, using tax brackets that increase as your income rises.
- Your employer usually withholds tax from each paycheck, so you do not have to pay it all at once when you file.
- You file a tax return once per year to report all your income and either receive a refund or pay what you still owe.
- State and local taxes work separately from federal taxes and vary depending on where you live and work.
How income tax brackets work
The federal government uses a progressive tax system, meaning the tax rate increases as your income increases. Your income is divided into brackets, and you pay a different rate on each bracket. For example, if you are single and earned $50,000 in 2024, you do not pay the same rate on all $50,000 — you pay the lowest rate on the first portion, a higher rate on the next portion, and so on.
The tax brackets change each year and depend on your filing status (single, married filing jointly, head of household, and so on). You can find the current brackets on the IRS website or in the instructions that come with Form 1040. A common mistake is thinking that moving into a higher bracket means all your income is taxed at that higher rate — it is not. Only the income within that bracket is taxed at that rate.
Types of income that are taxed
Wages and salaries are the most straightforward: your employer reports what you earned on a W-2 form, and you report that on your tax return. Self-employment income — money you earn from running your own business or freelancing — is also taxable and requires you to report it yourself on Schedule C.
Investment income includes interest from savings accounts, dividends from stocks, and capital gains when you sell an investment for more than you paid. Retirement account withdrawals are taxed as ordinary income in most cases. Rental income from property you own is taxable. The IRS sends you forms (1099-INT for interest, 1099-DIV for dividends, 1099-NEC for self-employment income, and others) that report these amounts to both you and the IRS, so they know what you should report.
How withholding works during the year
If you work as an employee, your employer withholds federal income tax from each paycheck based on information you provide on Form W-4. The W-4 asks about your filing status, number of dependents, and other income sources so your employer can estimate how much to withhold. The goal is to withhold roughly the amount of tax you will owe, so you do not have a large bill or refund at the end of the year.
If you are self-employed or have income that is not subject to withholding, you may need to make estimated tax payments four times per year (quarterly) to avoid penalties. These payments go directly to the IRS and count toward your total tax bill for the year. If you do not withhold or pay enough during the year, you will owe money when you file your return.
State and local income taxes
Most states collect their own income tax on top of federal tax, though a few states (Alaska, Florida, Nevada, South Dakota, Tennessee, Texas, Washington, and Wyoming) do not. State tax rates and brackets vary widely. Some states tax only wages, while others tax investment income and retirement withdrawals. A few states have local income taxes as well, collected by your city or county.
When you file your federal return, you also file a state return (if your state has income tax) and possibly a local return. State and local taxes are separate from federal taxes — you cannot straightforward pay one and skip the others. If you moved during the year or worked in multiple states, you may need to file returns in more than one state.
Deductions and credits that lower your tax bill
The IRS allows you to reduce your taxable income through deductions. You can either take the standard deduction (a fixed amount based on your filing status) or itemize deductions (add up specific expenses like mortgage interest, property taxes, and charitable donations). Most people take the standard deduction because it is simpler and results in a lower tax bill.
Tax credits are different from deductions — they reduce your tax bill dollar-for-dollar rather than reducing your income. Common credits include the Earned Income Tax Credit (EITC) for lower-income workers, the Child Tax Credit for parents, and the American Opportunity Credit for education expenses. Credits are often more valuable than deductions because of how directly they reduce what you owe.
What happens if you do not file or pay
If you owe taxes and do not file or pay, the IRS can charge you penalties and interest on the unpaid amount. The failure-to-file penalty is usually 5 percent of the unpaid tax for each month you are late (up to 25 percent total). The failure-to-pay penalty is 0.5 percent per month. Interest accrues daily on any unpaid tax. These penalties add up quickly, so filing even if you cannot pay when ready is better than not filing at all.
If you owe a significant amount, you can contact the IRS to set up a payment plan. The IRS also has programs for people in financial hardship. If you straightforward cannot pay, filing your return on time stops the failure-to-file penalty from growing, even though the failure-to-pay penalty and interest will continue.
Frequently Asked Questions
Do I have to file a tax return if I did not earn much money?
It depends on your income level and filing status. The IRS sets a threshold each year — if your income is below that threshold, you are not required to file. However, if your employer withheld taxes from your paycheck, you should file to get a refund. Check the IRS website for the current threshold based on your age and filing status.
What is the difference between a tax refund and a tax credit?
A refund is money the IRS returns to you because you overpaid your taxes during the year through withholding or estimated payments. A credit is a reduction in the tax you owe. Some credits are refundable, meaning if the credit is larger than your tax bill, the IRS sends you the difference as a refund.
Can I deduct my student loan interest?
Yes, you can deduct up to $2,500 of student loan interest per year on your federal tax return, even if you do not itemize deductions. This is called an "above-the-line" deduction. There are income limits — the deduction phases out at higher income levels — so check the IRS instructions for Form 1040 to see if you may have access to.
Why do I owe taxes if my employer withheld money from my paycheck?
Your employer estimates how much tax to withhold based on the W-4 you filled out, but the estimate may not be exact. If you had additional income, claimed too many dependents, or had a major life change, the withholding may be too low. When you file your return, the IRS calculates your actual tax bill and compares it to what was withheld.
What if I made a mistake on my tax return?
You can file an amended return using Form 1040-X to correct errors. You generally have three years from the original due date to file an amended return and claim a refund. If you owe additional tax, file the amended return as soon as possible to minimize penalties and interest.