The Internal Revenue Service (IRS) is the U.S. Treasury Department agency charged with administering and enforcing the Internal Revenue Code (federal tax law). It collects federal taxes (income, estate, gift, excise and other levies), issues refunds, processes returns and conducts audits to verify taxpayer compliance.
Key takeaways
– The IRS enforces federal tax laws and collects more than $5.1 trillion in revenue (FY 2024).
– Most individual taxpayers file Form 1040 (or 1040‑SR for seniors); corporations generally use Form 1120.
– Electronic filing is fastest and most reliable — 92.8% of taxpayers filed electronically in 2024.
– Audit rates are low for most filers: 0.44% for individual returns in FY 2023. Higher‑income filers face higher audit odds.
– The IRS is funded by a congressional appropriation that is divided into four statutory accounts (Taxpayer Services, Enforcement, Operations Support, Business Systems Modernization).
Brief history
– 1862: President Lincoln created the Office of the Commissioner of Internal Revenue to help fund the Civil War.
– 1913–1914: After ratification of the Sixteenth Amendment and enactment of income tax law, the Bureau of Internal Revenue issued the first Form 1040.
– 1953–1954: The agency was renamed the Internal Revenue Service; the standard filing deadline became April 15.
(Source: IRS history timeline.)
How the IRS collects revenue
– Payroll withholding: Employers withhold federal income tax and remit it to the IRS throughout the year.
– Estimated tax payments: Self‑employed taxpayers and businesses often make quarterly estimated payments.
– Annual reconciliation: Individual and business returns reconcile tax withheld/estimated with tax owed. Overpayments result in refunds; underpayments must be paid with the return or via an approved payment method.
– FY 2024 collections exceeded $5.1 trillion; the IRS processed 163.4 million individual returns and issued 104.8 million refunds (totaling about $329 billion) in 2024.
Tax returns — what to use and what to attach
– Individuals: Form 1040 (or 1040‑SR for seniors). Common attachments include W‑2s, 1099s and schedules:
• Schedule A — itemized deductions
• Schedule D — capital gains and losses
– Corporations: Form 1120 (with variations depending on entity type)
– Supporting documentation: pay statements, 1098 mortgage interest statements, receipts for deductible expenses, investment statements, and records of business income/expenses.
Best way to file a tax return (practical steps)
1. Gather documents
• W‑2s, 1099s (1099‑MISC, 1099‑NEC, 1099‑INT, 1099‑DIV), K‑1s, mortgage interest (1098), proof of deductible expenses, Social Security numbers, prior year return.
2. Choose filing method
• Electronic filing (e‑file) is recommended — fastest refunds and fewer errors. Use IRS Free File (if eligible), commercial tax software, or a tax professional.
• Paper filing by mail is allowed, but slows processing and refunds.
3. Complete the correct forms
• Use Form 1040 or 1040‑SR for individuals; attach relevant schedules and forms.
4. Review and sign
• For e‑file, follow software prompts. For paper returns, sign and date the return.
5. File and pay
• E‑file and choose direct deposit for refunds.
• If you owe, pay by IRS Direct Pay, Electronic Federal Tax Payment System (EFTPS), debit/credit card (fees may apply), or request an installment agreement if you can’t pay in full.
6. If you need more time
• File Form 4868 to request an automatic extension to file (but extension to file is not an extension to pay taxes owed).
How the IRS is funded
– The IRS operates on a budget appropriated by Congress. That appropriation is divided into four separate accounts:
• Taxpayer Services
• Enforcement
• Operations Support
• Business Systems Modernization
– Funds allocated to each account are statutorily restricted and may not be reallocated by the IRS. (Source: IRS budget & workforce.)
IRS audits — chances, triggers, and the process
– Audit odds
• FY 2023: 582,944 audits leading to $31.9 billion in recommended additional tax.
• Audit rate in FY 2023: ~0.44% for individual returns, 0.74% for corporate returns.
• High‑income filers face greater odds; for example, 8.7% of individuals making $10 million+ were audited across 2013–2021.
– Common triggers (raise audit risk)
• Large or unusual deductions for the filer’s income level (e.g., charitable deductions that exceed reported income)
• Large business losses or self‑employment income with little withholding
• Discrepancies between tax return and third‑party reports (W‑2s, 1099s)
• Math errors or incomplete returns (though many are corrected during processing)
– Audit process (practical steps if contacted)
1. Read the notice carefully — it explains what’s being examined and what documentation is requested.
2. Do not ignore the notice — respond by the deadline given, and do not provide sensitive information by phone or text unless you initiated the contact.
3. Gather records requested (receipts, bank statements, ledgers, tax forms).
4. Consider representation — CPAs, enrolled agents or tax attorneys can represent you before the IRS.
5. If you disagree with proposed changes, follow the appeals process outlined in the notice.
6. Keep copies of everything you send.
– Audit format: some audits are handled by mail; others are in‑person at an IRS office or the taxpayer’s place of business/accountant’s office.
Contacting the IRS — where to go and what tools to use
– Phone: Individual assistance at (800) 829‑1040 (Mon–Fri, generally 7 a.m.–7 p.m. local time). Other toll‑free numbers exist for businesses and specialty issues.
– Online tools: Interactive Tax Assistant (ITA), “Where to File” addresses, questions about refunds, payment tools, transcripts, and more are available at IRS.gov.
– Local offices: In‑person appointments available at local Taxpayer Assistance Centers (check IRS site for locations and hours).
– Mailing addresses: See IRS guidance for where to send returns, payments and non‑return forms.
Practical steps for common taxpayer needs
– To get a tax transcript: Use the IRS Get Transcript tool on IRS.gov or submit Form 4506‑T to request transcripts by mail.
– To set up a payment plan: Apply online for a short‑term extension or long‑term installment agreement via the IRS website.
– To protect against identity theft: Consider getting an Identity Protection PIN (IP PIN) from the IRS if you are a victim of identity theft or eligible through the IRS program.
– To dispute a bill or assessment: Follow the instructions on the notice; consider filing an appeal if you disagree.
– To find a tax preparer: Use IRS Directory of Federal Tax Return Preparers to check credentials; look for CPAs, enrolled agents, or attorneys for complex issues.
How to reduce audit risk (practical tips)
– Report all income shown on W‑2s and 1099s; reconcile discrepancies before filing.
– Keep clear documentation for deductions, especially for charitable gifts, business expenses, and home office claims.
– Avoid round numbers for large deductions unless they’re accurate and documented.
– Use reputable tax software or a qualified tax professional for complicated returns.
Fast facts
– FY 2024: Over $5.1 trillion collected; 163.4 million individual returns processed; 104.8 million refunds paid (about $329 billion).
– Electronic filing rate (2024): 92.8%.
– FY 2023 audits: 582,944 audits; 0.44% audit rate for individuals; recommended additional tax of $31.9 billion.
The bottom line
The IRS is the federal agency responsible for administering and enforcing federal tax law. Most taxpayers interact with it annually when filing returns or paying taxes. Electronic filing, accurate recordkeeping, timely payment (or setting up payment arrangements), and prompt, documented responses to notices are the most effective ways to minimize problems and speed refunds. While audits make headlines, the chance of audit is low for most taxpayers; higher income and large, unusual deductions increase audit risk.
Sources
– Investopedia: “What Is the IRS?” (source URL provided)
– Internal Revenue Service (IRS) — history timeline; filing season statistics; Form 1040/1040‑SR instructions; Form 1120 instructions; IRS audits guidance; 2023 Data Book; IRS contact pages; IRS budget & workforce information; Interactive Tax Assistant (ITA); Where to file and contact local IRS office pages. (See IRS.gov for each topic above.)
– Produce a personalized checklist for filing your next return (based on employment/gig/self‑employment status), or
– Walk through how to set up an IRS payment plan or request a transcript step‑by‑step. Which would you prefer?