The government imposes a tax by moving through a fixed chain: a constitutional grant of taxing power, a bill passed by both chambers of Congress and signed by the President, detailed regulations written by the Treasury Department and the IRS, and an administrative system that collects the money and penalizes noncompliance. State and local governments follow the same pattern under their own constitutions, with the added constraint that local authority exists only to the extent the state legislature grants it. Understanding how the government imposes a tax matters because every step in that chain creates rights, deadlines, and openings for the people who have to pay.
Where the Power to Tax Comes From
Federal taxing authority begins with Article I, Section 8, Clause 1 of the Constitution, the Taxing and Spending Clause. It gives Congress the power to “lay and collect Taxes, Duties, Imposts and Excises” to pay debts and provide for the national defense and general welfare.1Congress.gov. Constitution Annotated – Overview of Taxing Clause That one clause is the source of the entire federal revenue system.
The original text put two limits on it. Duties and excises had to be geographically uniform across the states, so Congress could not set a higher rate in one state than another.2Congress.gov. Article I, Section 8, Clause 1 – General Welfare And any “direct tax” had to be apportioned among the states by population, which made an income tax practically impossible.3Constitution Annotated. Overview of Direct Taxes The 16th Amendment, ratified in 1913, removed that barrier by authorizing Congress to tax incomes “from whatever source derived, without apportionment among the several States.”4National Archives. 16th Amendment to the U.S. Constitution – Federal Income Tax The modern income tax exists because of that single sentence.
Two other constitutional rules still bind Congress. The Export Clause prohibits any federal tax on goods exported from a state.5Legal Information Institute. Prohibition on Taxes on Exports The Origination Clause requires every revenue-raising bill to start in the House of Representatives.6Constitution Annotated. Origination Clause and Revenue Bills
Federal, State, and Local Authority Are Not the Same
Taxation is a concurrent power. The federal government and each state can impose taxes independently, drawing from separate sources of authority.
Federal authority is bounded only by the constitutional constraints above. State taxing power flows from each state’s own sovereignty, but it runs into two federal limits. The Commerce Clause blocks state taxes that discriminate against or unduly burden interstate commerce, tested under the Supreme Court’s four-part framework from Complete Auto Transit v. Brady.7Congress.gov. Apportionment Prong of Complete Auto Test for Taxes on Interstate Commerce And the doctrine of intergovernmental tax immunity, from McCulloch v. Maryland, prevents states from taxing federal operations.8Justia. McCulloch v. Maryland, 17 U.S. 316
Local governments have the narrowest authority. Under Dillon’s Rule, a city or county cannot impose any tax unless the state legislature has expressly granted the power or clearly implied it.9National League of Cities. Cities 101 – Delegation of Power Some states grant broader “home rule” authority, but even that cannot override state law. In practice, property taxes are the primary revenue tool local governments actually control.
How a Federal Tax Becomes Law
A new federal tax, or a change to an existing one, begins as a revenue bill introduced in the House of Representatives. The bill goes first to the House Committee on Ways and Means, the chief tax-writing committee in Congress.10United States Committee on Ways and Means. About the Committee on Ways and Means The committee holds hearings, hears from stakeholders, and marks up the bill, setting the actual rates, thresholds, and structure. Only after committee approval does the bill reach the full House floor.
If the House passes it, the Senate takes over, working through the Senate Finance Committee and often amending the text substantially. When the two chambers pass different versions, a conference committee negotiates a single unified bill, which must then clear both chambers again. The President can sign it into law or veto it; overriding a veto takes two-thirds of each chamber.11Constitution Annotated. Veto Power
How the Bill Gets Scored
Before any tax bill reaches a floor vote, Congress needs an official estimate of what it will raise or cost. The Joint Committee on Taxation (JCT) is the scorekeeper. Under the Congressional Budget Act of 1974, JCT revenue estimates are the binding fiscal projections for all tax legislation.12Joint Committee on Taxation. Revenue Estimating The staff projects revenue over a 10-year window, starting from the Congressional Budget Office’s baseline, and accounts for how taxpayers will change their behavior in response: shifting the timing of transactions, restructuring businesses, adjusting hours worked. A bill that looks like a revenue raiser on paper can score poorly if the JCT expects heavy avoidance.
Sunsets and Why Tax Rules Can Disappear
Not every tax law is permanent. Congress sometimes writes an expiration date into the statute, often for budgetary reasons. The Tax Cuts and Jobs Act of 2017 is the recent example: its individual provisions, including reduced rates and the $10,000 state and local tax deduction cap, were scheduled to expire after December 31, 2025.13Congress.gov. Tax Provisions in H.R. 1, the One Big Beautiful Bill Act Congress addressed the expiration through the One Big Beautiful Bill Act, signed on July 4, 2025, which made most of the TCJA individual changes permanent starting in 2026.14Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026, Including Amendments From the One Big Beautiful Bill A tax you pay today can change or vanish if the authorizing provision sunsets, so expiration dates are worth watching.
From Statute to Rules You Actually Follow
Congress writes tax law in broad strokes. The Internal Revenue Code tells you what is taxable, but it rarely spells out how to calculate or report a specific item. That work falls to the Treasury Department and the IRS.
Treasury regulations are the most authoritative form of tax guidance below the statute itself. The process follows the Administrative Procedure Act. Treasury publishes a proposed regulation in the Federal Register, opens a public comment window, considers the comments, and then publishes a final regulation as a Treasury Decision.15Office of the Law Revision Counsel. 5 U.S. Code 553 – Rule Making Taxpayers can rely on final and temporary regulations, though temporary ones expire after three years.16Congress.gov. Reliance on Treasury Department and IRS Tax Guidance Courts have struck down tax regulations where Treasury failed to follow proper notice-and-comment procedures.
Below regulations, the IRS issues revenue rulings that interpret the law as applied to specific facts. They carry less weight than regulations, but taxpayers can rely on them when their situation substantially matches the ruling’s facts.16Congress.gov. Reliance on Treasury Department and IRS Tax Guidance The public comment window is often the only realistic chance for individuals and businesses to influence how a tax will actually work before it becomes final.
How the Tax Reaches You
Once a tax is law and the regulations are written, collection is administrative. The IRS handles federal taxes under the Treasury Department. State departments of revenue manage state taxes. Local assessors and collectors handle property taxes. The basic mechanism at every level is the same: the government defines what you owe, you report and pay, and the government checks your work.
For most individuals, that starts with filing Form 1040 by the annual deadline.17Internal Revenue Service. About Form 1040, U.S. Individual Income Tax Return The IRS runs automated matching to flag discrepancies and audits returns to verify accuracy. When it believes you owe more, it can issue a notice of deficiency, levy bank accounts, or place liens on property.
Penalties compound quickly. The failure-to-file penalty is 5% of the unpaid tax for each month or partial month a return is late, capped at 25%.18Internal Revenue Service. Failure to File Penalty The failure-to-pay penalty is a separate 0.5% per month on unpaid balances, also capped at 25%. That rate drops to 0.25% per month if you filed on time and have an approved payment plan, and it jumps to 1% per month if you ignore a levy notice.19Internal Revenue Service. Failure to Pay Penalty Filing late with a balance due triggers both penalties at the same time.
How Long the IRS Has to Come After You
The IRS does not have unlimited time. The general rule gives the agency three years from the date a return was filed to assess additional tax.20Office of the Law Revision Counsel. 26 U.S. Code 6501 – Limitations on Assessment and Collection That stretches to six years if you omitted more than 25% of your gross income.21Internal Revenue Service. Time IRS Can Assess Tax There is no time limit in two situations: you never filed, or the return you filed was fraudulent. In those cases the IRS can assess tax indefinitely.
How You Can Push Back
The power to impose a tax comes with corresponding protections for the people paying it. The IRS recognizes ten fundamental taxpayer rights, including the right to pay no more than the correct amount, the right to challenge the IRS’s position, and the right to appeal in an independent forum.22Internal Revenue Service. Taxpayer Bill of Rights
Administrative Appeals
Most disputes settle without going to court. The IRS Independent Office of Appeals operates separately from the examination division that audited you, and conferences can happen in person, by phone, or in writing.23Internal Revenue Service. Appeals Process You generally have 30 days from the proposed adjustment letter to request an appeal. If the total at issue for each tax period is $25,000 or less, a brief written statement of disagreement is enough. Larger amounts require a formal written protest laying out the facts and legal basis, signed under penalty of perjury.
Tax Court
When appeals fail, the U.S. Tax Court is the only judicial forum where you can challenge an assessment without paying it first. After the IRS issues a statutory notice of deficiency, sometimes called a 90-day letter, you have 90 days to file a petition, or 150 days if the notice was sent to an address outside the United States.24Office of the Law Revision Counsel. 26 USC 6213 – Restrictions Applicable to Deficiencies; Petition to Tax Court The filing fee is $60, and fee waivers are available. Missing that deadline closes the Tax Court door for good, which makes it one of the most consequential deadlines in the entire tax system.