Essential tax terms to know before Tax Day

Understanding basic tax concepts helps you know how your income is taxed, which forms you need and how to prepare to file. Start with five basic terms: taxable income, withholding, Form W-4, Form W-2, and Form 1040.

Quick glossary: core tax terms

These terms explain how your tax bill is calculated, how taxes are collected from your pay and which documents connect your earnings to your return. The glossary below covers these concepts and others you’ll need to prep for tax season.

• Estimated tax: Quarterly payments some taxpayers make when withholding doesn’t fully cover their tax bill, common for self-employed workers or those with side income.
• Extension: An automatic six-month filing extension you get by submitting Form 4868 by Tax Day. It doesn’t extend your time to pay.
• Filing status: Your IRS category (single, married filing jointly, married filing separately, head of household, or qualifying surviving spouse) that affects your tax brackets, standard deduction and credits.
• Form 1040: The individual income tax return you file each year with the IRS.
• Itemize (Schedule A): Claiming specific deductible expenses, like mortgage interest or charitable gifts, instead of the standard deduction.
• Nontaxable income: Money or benefits not included in taxable income under federal law, such as certain gifts or inheritances. Source: IRS Publication 525.
• Refund: Money the IRS sends you when your total payments and credits exceed your total tax for the year.
• Standard deduction: A fixed amount that reduces your taxable income; most filers claim this instead of itemizing.
• Tax bracket: The rate that applies to the last dollar of your taxable income within the progressive U.S. tax system.
• Tax credit: A dollar-for-dollar reduction of your tax, often more valuable than a deduction.
• Taxable income: The portion of your income that is subject to federal income tax after allowable adjustments and deductions.
• W-2: The annual wage and tax statement from your employer showing pay and taxes withheld.
• W-4: The IRS form you give your employer to set your paycheck withholding. Update it after major life changes.
• Withholding: Money your employer withholds from each paycheck and sends to the IRS to prepay your estimated taxes. You adjust it through Form W-4.

Explore more tax resources.

Why do we pay taxes?

We pay taxes to fund government programs and services that benefit communities across the country. Federal income taxes support several shared priorities. These include health care, Social Security and national defense.

• Congress sets tax laws; the IRS administers them.
• Income taxes have been the federal government’s largest revenue source since 1950.
• Failing to pay on time can trigger penalties and interest.

What is taxable vs. nontaxable income?

Most money, property or services you receive count as taxable income. Common taxable income includes wages, salaries, tips, bonuses, commissions, interest, dividends and the fair market value of bartered goods or services. However, federal law excludes a few specific types of income.

• Common nontaxable income includes certain inheritances, life insurance death benefits, child support and some health benefits.
• Some items, like Social Security benefits, can be partly taxable depending on your total income.
• Always check current IRS rules before you file.

What is withholding tax, and how does it work?

Withholding is the amount your employer sends to the IRS from each paycheck to cover your estimated income tax. Withhold too much, and you’ll get a refund. Withhold too little, and you may owe money when you file.

• Check your pay stub and review your year-to-date federal income tax withholding to help avoid an unexpected bill or underpayment penalties.
• Use the IRS Tax Withholding Estimator and update Form W-4 after major life events, such as marriage, a new job, a child or a home purchase.
• If you’re self-employed, withholding usually doesn’t apply. See the estimated tax section below.

Which basic tax forms do you need?

Many filers encounter three core forms because each plays a different role in the tax process. Form W-4 sets paycheck withholding, Form W-2 reports annual wages and taxes withheld, and Form 1040 is used to file an individual federal income tax return.

1. W-4: Tells your employer how much to withhold. (About Form W-4)
2. W-2: Your employer’s annual wage and tax statement, sent to you and the IRS. (About Form W-2)
3. 1040: The individual income tax return you use to file. (About Form 1040)

What are the five tax filing statuses?

Your filing status affects your standard deduction, tax brackets and credits. Only one status applies for the year, generally based on your situation as of December 31.

The five statuses are:

1. Single
2. Married filing jointly
3. Married filing separately
4. Head of household
5. Qualifying surviving spouse with a dependent child

Unsure which status fits you? The IRS Interactive Tax Assistant can help.

Should you take the standard deduction or itemize?

Choose the option that lowers your taxable income the most. The standard deduction is a fixed amount based on your filing status. Itemizing may help if deductible expenses, such as medical costs, mortgage interest, state and local taxes up to limits, or charitable gifts, exceed your standard deduction.

• Compare the standard deduction with your eligible itemized deductions before deciding.
• You can “run it both ways” using Schedule A to compare outcomes.
• The IRS announces new inflation-adjusted amounts each fall, so check the IRS newsroom for the latest figures.

What are the important tax deadlines?

Staying on top of these dates helps you avoid IRS penalties. Keep in mind that an extension gives you more time to file, not more time to pay. Pay by the tax due deadline (April 15) to avoid penalties and interest.

• April 15: Deadline to file individual returns and pay any tax due. If April 15 falls on a weekend or legal holiday, the deadline moves to the next business day.
• October 15: Deadline to file if you requested an extension by Tax Day using Form 4868.
• Estimated quarterly tax payments (common for self-employed taxpayers and those with side income): generally due April 15, June 15, September 15 and January 15.

Want to learn more about reducing your current or future tax burden? Explore more tax planning insights so you can prepare with confidence.

Not sure what to do with your tax refund?