How Income Taxes Work

By: Kevin Bonsor & Dave Roos
America has one of the most complicated tax systems in the world, and it grows more complex every year. How did it get this way? See more tax pictures.

There's nothing quite like the excitement and pride of receiving your very first paycheck. You worked hard for a solid month, and here's your much-deserved compensation. But wait a second ... what's the story with this line that says "net pay?" That can't be your actual salary, could it? What happened to all of your money? By the time you get your paycheck, it's been cut up like a pizza, with several government agencies taking a piece of the pie. Exactly how much money is withheld from each check varies from person to person, company to company and state to state. However, almost every income earner has to pay federal income tax.

We generally don't think much about taxes except during the annual tax season. It's probably the most dreaded time of the year for millions of Americans, yet we circle it on our calendars, along with holidays and birthdays. But little joy is connected to April 15, the deadline for filing tax forms. (This deadline doesn't always fall on the 15th. In 2012, Tax Day was Tuesday, April 17 because the 15th was a Sunday and the 16th was a holiday in Washington, D.C. [source: Kaufman].)


The American tax system is a huge machine with a tax code that seems more complex than rocket science. In this article, we will examine how individual income taxes work, take a look at the history of income taxes in the United States and consider two alternative tax plans.


Taxes in Early America

Taxes have always left a sour taste in the mouths of American citizens. This national hatred for taxes dates back to the tax burden placed on the American colonies by Great Britain. Colonists were taxed for every consumer good, from tea and tobacco to legal documents. This "taxation without representation" led to many revolts, such as the Boston Tea Party, in which colonists dumped tea into the Boston Harbor rather than pay the tax on it.

Although the American colonists fought for independence from British rule and British taxes, once the United States government formed, its main source of revenue was derived from placing customs and excise taxes on the same items that had been taxed by Great Britain. In 1812, in an effort to support an expensive war effort, the U.S. government imposed the first sales tax, which was placed on gold, silverware, jewelry and watches. In 1817, internal taxes (taxes on goods and land) were terminated, and the government relied on tariffs (taxes on imports or exports) to support itself. It wasn't until 1862 that the United States imposed the first national income tax [source: Tax Foundation].


To support the Union Army during the American Civil War, Congress passed tax laws in both 1861 and 1862. The office of Commissioner of Internal Revenue was established by the Tax Act of 1862, which stated that the commissioner would have the power to levy and collect taxes. The office also was given the authority to seize property and income in order to enforce the tax laws. These powers remain pretty much the same today, although the Internal Revenue Service (as it's been known since the 1950s) will tell you that enforcement tactics have been toned down a bit [source: IRS].

The First Income Tax

The first income tax was instituted by Congress to help pay for the American Civil War.
Universal History Archive/Getty Images

In 1863, the federal government collected the first income tax. This graduated tax was similar to the income tax we pay today. Those who earned $600 to $10,000 per year paid at a rate of 3 percent. Those who earned in excess of $10,000 paid 5 percent. A flat-rate tax was imposed in 1867. Five years later, in 1872, the national income tax was repealed altogether since the Civil War was long over and revenue needs had declined. The federal government went back to relying mainly on tariffs and excise taxes, such as liquor taxes [source: U.S. Dept. of Treasury].

Spurred on by the Populist Party's 1892 campaign to reduce high tariffs, Congress passed the Income Tax Act of 1894 to make up the difference. This act taxed 2 percent of personal income that was more than $4,000, which only affected the top 10 percent. The income tax was short-lived, as the U.S. Supreme Court struck it down only a year after it was enacted. The justices wrote that the income tax was unconstitutional because it failed to abide by a constitutional guideline. This guideline required that any tax levied directly on people must be levied in proportion to a state's population [source: Our Documents].


In 1913, the income tax became a permanent part of the U.S. government. Congress avoided the constitutional roadblock mentioned above by passing a constitutional amendment. The 16th Amendment reads, "The Congress shall have power to lay and collect taxes on incomes, from whatever source derived, without apportionment among the several States, and without regard to any census or enumeration." The 16th Amendment gave the government the power to levy taxes on people regardless of state population. The Underwood Tariff Act of 1913 included an income-tax section that initiated the progressive system we use today: Those who earned more than $3,000 ($4,000 for married couples) were subject to a 1 percent tax, which increased depending on income and topped out at 7 percent [source: IRS].

During World War II, the federal government began withholding taxes, also known as the pay-as-you-earn taxation system. This gave the government the steady flow of money needed to finance the war effort.

In 2014, the tax brackets range from 10 percent to 39.6 percent [source: Bankrate].


The Tax Process

If you've ever filled out a 1040, you know the U.S. tax system and the agency that keeps it going are complex and mystifying entities. Get the lowdown on this essential piece of the U.S. government.

While most Americans only think about taxes when April approaches, the tax collection process actually runs all year long.

The process begins when you start a new job. You and your employer agree on your compensation — an hourly wage or an annual salary — which adds up to your gross or "before tax" income. The next thing you do is fill out a W-4 form. The W-4 form is like a miniature income tax survey. It determines if you are single or married, if you have children or other dependents, if your spouse works and if you have childcare expenses. These are called your personal allowances. The number of allowances listed on the W-4 form determines how much income tax your employer will withhold from each paycheck.


Why does your company do this? Because employers are required by law to withhold income tax from all employee paychecks and deposit the money in a Federal Reserve Bank. This is how the federal government maintains a steady stream of income while also drawing interest on your tax dollars. Instead of paying taxes once a year in April, you really pay them all year long.

The W-4 form is important because it ensures that you aren't paying either too much or too little in federal income tax during the year. Some people love to get a big refund check when they file their tax return in April. But what that really means is that they paid too much income tax during the year. They could have put that money in the bank, invested it, or bought something useful with it rather than letting the IRS borrow it. By adjusting the number of allowances on the W-4 form, you can decrease or increase the amount withheld from each check. That way, there are no big checks or big bills in April. Check your W-4 annually to make sure the information is up to date.


Filing Income Taxes

Filing income taxes in April is akin to "settling up" with the IRS. In reality, you've been paying taxes all year long. In April, all you are doing is determining if you paid the right amount. If you paid too much, you get a refund; too little and you're writing another check. Income tax forms like the 1040 are notoriously confusing, but that's because they're based on a U.S. tax code that's more than 5,000 pages long [source: Shinske]. Here are the basic steps to completing a tax return:

  1. Start by adding up your gross income, which includes salary or wages from a job, investment interest income, pensions and annuities. If you have job, your employer will send you a W-2 form in the mail which shows how much you earned and how much income tax was already withheld.
  2. Subtract any adjustments (examples: alimony that you paid, deposits in retirement plans, self-employment estimated taxes paid, moving expenses, interest that you paid on a student loan, etc.). The difference is called adjusted gross income (AGI).
  3. Once you know your AGI, you have two choices: Either subtract a standard deduction, or subtract itemized deductions, whichever is greater. Itemized deductions might include medical and dental expenses, charitable contributions, interest on home mortgages, and state and local taxes from the previous year.
  4. Next, subtract personal exemptions. For 2013, the IRS allows you to subtract $3,900 each for you, your spouse and each dependent if your AGI is under a certain amount [source: IRS]. Everything left over is called your taxable income.
  5. This is where it gets a little complicated, because the United States uses a marginal or progressive tax rate system. The more you earn, the higher your tax rate. To determine exactly how much you owe, look up your taxable income on the IRS tax table. Find the number that matches your filing status: single, married filing jointly, married filing separately, head of household, or qualifying widow(er) with dependent child, which is the same as "married filing jointly." That number is your gross tax liability. Don't worry, you have one more chance to lower your tax bill.
  6. From your gross tax liability, subtract any credits. The Child Tax Credit is a big one: $1,000 for each qualifying child. Other credits include the Earned Income Tax Credit (or Earned Income Credit) for low-income working families, which can be as much as $6,000, and the Child and Dependent Care Credit for childcare expenses.
  7. The final number is your net tax. If it's a positive number, you owe money to the IRS. If it's negative, you're getting a refund.

You must file your federal income tax return and pay any taxes owed by April 15. Filing or paying late results in penalties and interest that accrues over time. If you are due a refund, the IRS mails most of them out within two weeks of receiving a return. You could also have the money electronically deposited directly into a bank account.


Alternative: Flat Tax

Humorist and travel writer Stanton Delaplane once offered this lighthearted suggestion for a simplified tax form: "How much money did you make last year? Mail it in." While that may be a drastic way to change the tax system, there has been no shortage of people proposing new tax systems since the 16th Amendment was passed in 1913. If you follow presidential campaigns, there is usually talk from some of the candidates on revising the tax system. Here's a quick look at two of these alternative tax plans.

We currently use a marginal tax system, also called a graduated tax, in which the percentage you pay in taxes varies based on your income. Under a flat tax system, everyone pays the same tax rate no matter how much they earn. Former presidential candidate Steve Forbes proposed a 17 percent flat tax in 1996 and 2000, and Rick Perry floated a 20 percent flat tax in his 2012 presidential campaign [source: Tax Policy Center].


Proponents of a flat-tax system say that it would do away with the complicated tax code and tax forms. The flat tax would need only one form, about the size of a postcard and consisting of only 10 lines. You would merely add up wage, salary and pension income, subtract any personal allowances and pay 17 percent of your taxable income. Deductions and credits would be eliminated under this type of plan. (Perry's proposal did allow a few deductions such as mortgage interest).

Critics of the flat tax say that it would favor the wealthy. Under Rick Perry's plan, a married couple with two children earning $31,000 would lose $5,000 in credits, while the same earning $424,900 would owe nearly $45,000 less in taxes [source: Rampell].


Alternative: National Sales Tax

Some people feel America should do away with paying income tax altogether and switch to a national sales tax of 10 to 25 percent on all goods and services.

Even more controversial than the flat tax is the idea of abolishing the federal income tax entirely by repealing the 16th Amendment. In place of an income tax, some propose the use of a national sales tax. Many countries around the world levy a national sales tax, also called a value-added tax or VAT. The difference is that most of those countries also collect income taxes. The U.S. backers of a national sales tax want to get rid of the IRS and charge a flat 10 to 25 percent on all retail purchases of new goods and services [source: Montgomery].

What are the benefits of a national sales tax? Like the flat tax, a national sales tax makes tax collection vastly simpler. Workers could keep their entire paycheck and use that money to buy the things that they need.


Proponents of the so-called Fair Tax — a version of the national sales tax — include a provision called a pre-bate. This is a monthly check mailed by the government to lower-income families to subsidize their purchases. Advocates of a national sales tax also argue that a consumption tax collects revenue from everyone, even illegal immigrants, tax dodgers and tourists from other countries [source:].

Opponents of a national sales tax say it would put an unfair burden on the middle and lower classes, who buy a lot of the products that would be taxed. It might reduce consumer spending, thereby slowing the economy. They add that in order for a national sales tax to be fair, it should be applied to the purchase of stocks and bonds in addition to consumer goods. Under the Fair Tax proposal, investments are not taxed, although brokers' fees would be [source:].

Taxes are a bitter subject in almost every country, and the United States has had a decidedly tumultuous relationship with the issue. America has one of the most complicated tax systems in the world, and it grows more complex every year. In the end, whether you agree with paying taxes or not, you probably have April 15 circled on your calendar, embedded in your brain and on your list of dreaded days.

For more information on taxes and related topics, check out the links on the next page.


Lots More Information

Related Articles


  • "FAQs: How does the FairTax affect illegal immigration?" (Feb. 7, 2014)
  • "FAQs: What happens to the stock market, mutual funds and retirement funds?" (Feb. 7, 2014)
  • IRS. "Brief History of IRS." (Feb. 7, 2014)
  • IRS. "Personal Exemptions and Dependents." (Feb. 7, 2014)
  • Kaufman, Wendy. "Why Tax Day Falls on April 17 This Year." NPR. April 13, 2012. (Feb. 7, 2014)
  • Montgomery, Lori. "Once Considered Unthinkable, U.S. Sales Tax Gets Fresh Look." The Washington Post. May 27, 2009. (Feb. 7, 2014)
  • Our Documents. "16th Amendment to the U.S. Constitution: Federal Income Tax (1913)." (Feb. 12, 2014)
  • Rampell, Catherine. "How Rick Perry's Tax Plan Would Affect You." The New York Times. Oct. 25, 2011. (Feb. 7, 2014)
  • Shinske, Caryn. "Leonard Lance claims federal tax code contains 4 million words, is 7 times as long as Bible." Politifact. April 15, 2013. (Feb. 7, 2014)
  • Tax Foundation. "History of the Income Tax in the United States." Infoplease. (Feb. 12, 2014)
  • U.S. Dept. of Treasury. "History of the U.S. Tax System." Almanac of Policy Issues. (Feb. 12, 2014)