The IRS is the federal agency that collects income taxes and enforces tax law in the United States
IRS stands for Internal Revenue Service. It is a bureau of the U.S. Department of the Treasury, which means it answers to the federal government, not to individual states. The IRS collects the income taxes that you pay on wages, investments, and self-employment income. It also enforces the tax code — the set of rules that determine what you owe, what deductions you can take, and what happens if you do not pay.
When you file a tax return each year, you are sending information to the IRS. The IRS uses that return to check whether you paid the right amount of tax. If you paid too much, they send you a refund. If you paid too little, they send you a bill. If you do not file at all and you are required to, the IRS can pursue collection actions against you.
The IRS also manages tax credits and deductions that reduce what you owe — things like the Earned Income Tax Credit, child tax credits, and deductions for mortgage interest or charitable donations. These programs are written into federal tax law, and the IRS administers them.
Key Takeaways
- The IRS is a federal agency that collects income taxes and enforces tax law across all 50 states.
- You file your annual tax return with the IRS to report your income and claim deductions or credits that reduce what you owe.
- The IRS determines whether you paid the correct amount of tax and issues refunds or bills based on your return.
- The IRS also administers federal tax credits and deductions that are part of the tax code.
- The IRS has the authority to audit returns, assess penalties, and pursue collection if you owe back taxes.
How the IRS collects taxes and processes returns
Most people encounter the IRS once a year, when they file a tax return. If you work as an employee, your employer withholds federal income tax from your paycheck and sends it to the IRS throughout the year. When you file your return, the IRS compares what was withheld to what you actually owe based on your income, deductions, and credits.
If you are self-employed or have income that is not subject to withholding — such as investment income or rental income — you may owe estimated tax payments to the IRS four times a year. The IRS uses these payments to collect tax as you earn it, rather than waiting until you file your return.
The IRS processes millions of returns each year. Most are processed without any contact from the IRS. However, the IRS may select a return for audit, which means an IRS agent will review your records to verify that the information on your return is correct.
What the IRS can do if you owe taxes
If you owe back taxes — taxes from a previous year that you did not pay — the IRS has several tools to collect the debt. The IRS can place a tax lien on your property, which gives the government a legal claim to your assets. The IRS can also issue a tax levy, which allows it to seize money from your bank account or wages to pay what you owe.
The IRS can also assess penalties and interest on unpaid taxes. Penalties are charges added to your bill for failing to pay or file on time. Interest is a percentage that grows each month you do not pay. Both penalties and interest can significantly increase the amount you owe.
If you owe taxes and cannot pay in full, you can contact the IRS to discuss payment options. The IRS offers installment agreements, which allow you to pay your debt over time in monthly payments. You can also request an Offer in Compromise, which is a settlement where you pay less than the full amount you owe, though this is only available in specific circumstances.
The difference between the IRS and state tax agencies
The IRS collects federal income tax, which goes to the U.S. Treasury and funds federal programs. Most states also collect their own income tax, which funds state and local programs. These are separate systems with separate rules.
When you file your federal tax return with the IRS, you typically also file a state tax return with your state's tax agency. The rules, rates, and deductions differ between federal and state tax. For example, a deduction that is allowed on your federal return may not be allowed on your state return, or vice versa. Some states do not collect income tax at all — they fund state government through sales tax, property tax, or other sources.
If you owe back taxes to both the IRS and your state, you will need to address each debt separately. The IRS cannot collect state taxes for you, and your state cannot collect federal taxes for you.
How to contact the IRS
The IRS operates a phone line where you can ask questions about your taxes, your return, or your account. The main IRS phone number is 1-800-829-1040. Wait times can be long, especially during tax season (January through April). The IRS also has a website at irs.gov where you can find forms, publications, and answers to common questions.
If you need to speak with an IRS agent in person, you can visit a local IRS office. The IRS website has a tool to find the office nearest you. You can also mail correspondence to the IRS, though responses by mail take longer than phone or in-person contact.
If you are being audited or owe a significant amount of taxes, you may want to work with a tax professional — a certified public accountant (CPA), enrolled agent, or tax attorney. These professionals can represent you before the IRS and help you understand your options.
Common reasons the IRS contacts you
The IRS contacts taxpayers for several reasons. The most common is an audit, where the IRS asks you to verify information on your return. An audit can be conducted by mail, by phone, or in person at an IRS office. The IRS will tell you which documents to bring or send.
The IRS may also contact you if there is a discrepancy between your return and information the IRS received from your employer, bank, or other source. For example, if your employer reports that you earned $50,000 but your return shows $40,000, the IRS will ask you to explain the difference.
If you owe taxes and have not paid, the IRS may send you a notice demanding payment. These notices include information about what you owe, how to pay, and what will happen if you do not respond. It is important to respond to IRS notices, even if you disagree with what they say, because ignoring them can result in additional penalties and collection action.
Frequently Asked Questions
Is the IRS the same as the Treasury Department?
No. The IRS is a bureau within the Treasury Department. The Treasury Department oversees the IRS and other agencies that manage federal finances, including the Bureau of Engraving and Printing and the U.S. Mint. The IRS specifically handles tax collection and enforcement.
Do I have to file a tax return every year?
Not everyone is required to file. Whether you must file depends on your income, age, and filing status. Generally, if your income is below a certain threshold set by the IRS each year, you do not have to file. However, if taxes were withheld from your pay, filing a return may result in a refund, so many people file even if they are not required to.
What happens if I do not pay my taxes?
The IRS will send you notices demanding payment. If you do not respond or pay, the IRS can place a lien on your property, levy your bank account or wages, or take other collection action. Penalties and interest will continue to grow on the unpaid amount. You can contact the IRS to discuss payment options before collection action begins.
Can the IRS take my house or car?
The IRS can place a lien on your house or car, which gives the government a legal claim to the property. However, the IRS typically does not seize and sell property unless the debt is very large and other collection methods have failed. If you owe taxes and are concerned about your property, contact the IRS to discuss payment options or hardship relief.
What is an IRS refund?
An IRS refund is money the IRS returns to you when you have paid more in federal income tax than you actually owe. This happens when your employer withholds too much tax from your paycheck, or when you are may have access to to tax credits that reduce what you owe below what was already paid. Refunds are typically issued within a few weeks of filing your return.