Tax Glossary
Plain-language definitions of common tax terms. Whether you're a first-time filer or a seasoned professional, find clear explanations for every concept.
A
Above-the-Line Deduction
Deductions subtracted from gross income to arrive at Adjusted Gross Income (AGI), available regardless of whether you itemize. Common above-the-line deductions include contributions to traditional IRAs, student loan interest (up to $2,500), self-employment tax (employer-equivalent portion), HSA contributions, educator expenses (up to $300), and alimony payments (for pre-2019 agreements). These are particularly valuable because they reduce AGI, which may unlock additional tax benefits that have AGI-based phase-outs.
deductionsAdjusted Gross Income (AGI)
Your total gross income minus specific deductions (called "adjustments to income"). AGI is a key figure on your tax return because it determines eligibility for many deductions and credits. It includes wages, salaries, interest, dividends, business income, capital gains, and retirement distributions, minus adjustments like student loan interest, IRA contributions, and self-employment tax.
incomeAlternative Minimum Tax (AMT)
A parallel tax system designed to ensure high-income taxpayers pay at least a minimum amount of tax. The AMT recalculates income tax after adding certain tax preference items back into adjusted gross income. For 2025, the AMT exemption is $85,700 for single filers and $133,300 for married filing jointly.
tax-typesAmended Tax Return (Form 1040-X)
A form filed to correct errors on a previously filed tax return. Common reasons include forgetting to report income, claiming incorrect deductions, or changing your filing status. You generally have three years from the original filing date to amend. Amended returns must be filed separately for each tax year and cannot be e-filed if amending a return from before 2019.
formsAmerican Opportunity Tax Credit (AOTC)
A partially refundable education tax credit of up to $2,500 per student for the first four years of post-secondary education. It covers 100% of the first $2,000 in qualified education expenses and 25% of the next $2,000. Up to $1,000 (40%) is refundable. The credit phases out at MAGI between $80,000 and $90,000 ($160,000-$180,000 for joint filers). The student must be enrolled at least half-time and not have completed four years of higher education.
creditsAmortization
The process of spreading the cost of an intangible asset over its useful life for tax purposes. Common amortizable assets include patents, copyrights, trademarks, goodwill, franchise agreements, and business startup costs. Most intangible assets acquired in a business purchase are amortized over 15 years under Section 197. Amortization reduces taxable income similarly to depreciation but applies to intangible rather than tangible assets.
businessC
C Corporation
The default corporate structure under U.S. tax law, where the corporation is a separate tax entity that pays corporate income tax at a flat 21% rate. When profits are distributed as dividends to shareholders, they are taxed again at the individual level (qualified dividends at 0%, 15%, or 20%), resulting in "double taxation." C corps have no restrictions on number or type of shareholders and can issue multiple classes of stock. They are commonly used by companies seeking venture capital or planning an IPO.
businessCapital Gains
The profit earned from selling a capital asset (stocks, bonds, real estate, etc.) for more than its purchase price. Short-term capital gains (assets held less than one year) are taxed at your ordinary income rate. Long-term capital gains (held over one year) are taxed at preferential rates of 0%, 15%, or 20% depending on your taxable income.
incomeCapital Loss
The loss incurred when you sell a capital asset for less than its purchase price. Capital losses first offset capital gains of the same type (short-term against short-term, long-term against long-term), then any remaining losses offset gains of the other type. If net losses remain, you can deduct up to $3,000 per year ($1,500 if married filing separately) against ordinary income. Unused losses carry forward indefinitely to future tax years.
incomeCharitable Contribution Deduction
An itemized deduction for donations to qualified charitable organizations. Cash donations are generally deductible up to 60% of AGI. Donations of appreciated property (stocks, real estate) are deductible at fair market value up to 30% of AGI, with the added benefit of avoiding capital gains tax on the appreciation. You must have written acknowledgment for any single donation of $250 or more.
deductionsChild Tax Credit
A tax credit of up to $2,000 per qualifying child under age 17. Up to $1,700 of the credit is refundable (Additional Child Tax Credit). The credit begins to phase out at $200,000 of modified AGI ($400,000 for married filing jointly). To qualify, the child must have a Social Security number, be claimed as your dependent, and live with you for more than half the year.
creditsCryptocurrency Taxation
The IRS treats cryptocurrency as property, not currency. Selling, trading, or using crypto to buy goods/services creates a taxable event. Capital gains rules apply: short-term (held under 1 year) taxed at ordinary rates, long-term (over 1 year) at preferential rates. Mining and staking income are taxed as ordinary income when received. Starting in 2025, crypto brokers must issue Form 1099-DA reporting transactions.
incomeD
Dependent
A qualifying child or qualifying relative you support financially who can be claimed on your tax return. Claiming a dependent can qualify you for various tax benefits including head of household filing status, child tax credit, earned income credit, and dependent care credit. A qualifying child must be under 19 (or 24 if a student), live with you for more than half the year, and not provide more than half of their own support.
filingDepreciation
The gradual deduction of the cost of a business asset over its useful life. Instead of deducting the full cost in the year of purchase, you spread it over several years. Common methods include straight-line depreciation and MACRS (Modified Accelerated Cost Recovery System). Section 179 allows immediate expensing of qualifying assets up to $1,220,000 in 2025.
businessE
Earned Income
Income received from active work or self-employment, as opposed to passive or investment income. It includes wages, salaries, tips, bonuses, commissions, and net self-employment income. Earned income is important because it determines eligibility for the Earned Income Tax Credit, IRA contributions, and the Child and Dependent Care Credit. It does not include interest, dividends, capital gains, pensions, Social Security benefits, or rental income.
incomeEarned Income Tax Credit (EITC)
A refundable tax credit for low-to-moderate-income working individuals and families. The credit amount depends on your income, filing status, and number of qualifying children. For 2025, the maximum EITC ranges from $632 (no children) to $7,830 (three or more children). Because it's refundable, you can receive it even if you owe no tax.
creditsEffective Tax Rate
The average rate at which your income is taxed, calculated by dividing your total tax liability by your total taxable income. Unlike the marginal rate (which applies only to the last dollar earned), the effective rate reflects what you actually pay overall. It is always lower than your marginal rate because of the progressive tax bracket system.
tax-typesEstate Tax
A federal tax on the transfer of a deceased person's assets to their heirs. The estate tax applies only to estates exceeding the exemption threshold, which is $13.99 million per individual in 2025 (effectively $27.98 million for married couples). Estates above the threshold are taxed at rates up to 40%. The exemption is scheduled to be roughly halved after 2025 when current provisions sunset. Some states impose their own estate taxes with lower thresholds.
tax-typesEstimated Tax Penalty
A penalty charged when you don't pay enough tax throughout the year via withholding or estimated tax payments. You generally owe the penalty if you owe at least $1,000 when you file and you paid less than 90% of this year's tax or 100% of last year's tax (110% if your AGI exceeded $150,000). The penalty is calculated as interest on the underpayment.
filingF
FATCA (Foreign Account Tax Compliance Act)
A U.S. law requiring foreign financial institutions to report accounts held by U.S. taxpayers to the IRS. On the individual side, U.S. persons with foreign financial assets exceeding $50,000 (single) or $100,000 (joint) at year-end must report them on Form 8938 filed with their tax return. Thresholds are higher for U.S. persons living abroad ($200,000/$400,000). FATCA is separate from FBAR requirements, and you may need to file both. Non-compliance can result in a $10,000 penalty per form.
internationalFBAR (Foreign Bank Account Report)
A report (FinCEN Form 114) required of U.S. persons who have a financial interest in or signature authority over foreign financial accounts with an aggregate value exceeding $10,000 at any time during the calendar year. Filed electronically with the Financial Crimes Enforcement Network (FinCEN), not with the IRS. The deadline is April 15 with an automatic extension to October 15. Penalties for non-compliance are severe: up to $16,117 per violation for non-willful failures and the greater of $161,176 or 50% of account balance for willful violations.
internationalFICA (Federal Insurance Contributions Act)
The payroll taxes that fund Social Security and Medicare. Employees pay 7.65% of their wages (6.2% for Social Security on the first $176,100 of earnings in 2025, plus 1.45% for Medicare on all earnings). Employers match this amount. Self-employed individuals pay both portions (15.3%) through self-employment tax. An additional 0.9% Medicare surtax applies to earnings above $200,000 (single) or $250,000 (married filing jointly).
tax-typesFiling Status
Your tax filing classification that determines your standard deduction amount, tax bracket thresholds, and eligibility for certain credits. The five filing statuses are: Single, Married Filing Jointly, Married Filing Separately, Head of Household, and Qualifying Surviving Spouse. Your status is generally determined by your marital status on December 31 of the tax year.
filingFlexible Spending Account (FSA)
An employer-sponsored account that lets you set aside pre-tax dollars for qualified medical expenses or dependent care costs. For 2025, the health FSA contribution limit is $3,300. Unlike HSAs, FSAs have a "use it or lose it" rule, though employers may offer a grace period of up to 2.5 months or allow a carryover of up to $640. Dependent care FSAs allow up to $5,000 per year for childcare expenses.
deductionsForeign Tax Credit
A dollar-for-dollar credit against your U.S. tax liability for income taxes paid to foreign governments. It prevents double taxation on income earned abroad. You can claim the credit on Form 1116 or, for amounts under $300 ($600 for joint filers), directly on Form 1040 without filing Form 1116. The credit is limited to the U.S. tax attributable to your foreign-source income. Unused credits can be carried back one year and forward ten years.
internationalForm 1040 (US Individual Income Tax Return)
The standard federal income tax return form filed by US individual taxpayers. All taxpayers use Form 1040, with additional schedules as needed (Schedule A for itemized deductions, Schedule C for business income, Schedule D for capital gains, etc.). The simplified forms 1040-EZ and 1040-A were eliminated after 2017, replaced by the redesigned 1040 with supplemental schedules.
formsG
Gift Tax
A federal tax on transfers of money or property to another person while receiving nothing (or less than full value) in return. The annual gift tax exclusion allows you to give up to $19,000 per recipient in 2025 without filing a gift tax return. Gifts above this amount count against your lifetime exemption ($13.99 million in 2025, shared with the estate tax exemption). Gifts to spouses (who are U.S. citizens), charities, and payments made directly to educational or medical institutions are unlimited and exempt.
tax-typesGross Income
The total of all income you receive during the year from all sources before any deductions or adjustments. This includes wages, salaries, tips, interest, dividends, business income, rental income, alimony received (for pre-2019 agreements), capital gains, and retirement distributions. It does not include tax-exempt income like certain municipal bond interest or gifts.
incomeH
Head of Household
A filing status for unmarried taxpayers who pay more than half the cost of maintaining a home for a qualifying dependent. This status provides a larger standard deduction ($21,900 in 2025) and more favorable tax brackets than Single filing status. You must be unmarried or "considered unmarried" on the last day of the year and have paid more than half the cost of keeping up a home for a qualifying person.
filingHealth Savings Account (HSA)
A triple-tax-advantaged savings account available to those with high-deductible health plans (HDHPs). Contributions are tax-deductible, growth is tax-free, and withdrawals for qualified medical expenses are tax-free. For 2025, contribution limits are $4,300 for self-only coverage and $8,550 for family coverage, with an additional $1,000 catch-up contribution for age 55+. Unused funds roll over year to year and the account is portable.
deductionsHeffingskorting (Dutch Tax Credits)
The Dutch system of tax credits that directly reduce the amount of tax owed. The two main credits are the algemene heffingskorting (general tax credit, up to €3,362 in 2025) and the arbeidskorting (employment tax credit, up to €5,532). Both credits phase out as income increases. These are automatically applied by employers through payroll, similar to how the UK's PAYE works.
internationalHome Office Deduction
A deduction for the business use of your home, available to self-employed individuals who use a portion of their home regularly and exclusively for business. Two methods: the simplified method ($5 per square foot, max 300 sq ft = $1,500) or the regular method (actual expenses proportional to office area). This deduction is NOT available to W-2 employees working from home.
deductionsI
Internal Revenue Service (IRS)
The US federal agency responsible for collecting taxes and enforcing tax laws. The IRS processes over 150 million individual tax returns annually, issues refunds, conducts audits, and provides taxpayer assistance. The agency is funded through congressional appropriations and has been undergoing a major modernization effort since 2022 with increased funding from the Inflation Reduction Act.
filingIRS Audit
An examination of your tax return by the IRS to verify that income, expenses, and credits are reported accurately. Audits can be conducted by mail (correspondence audit), at an IRS office (office audit), or at your home/business (field audit). The IRS generally has three years from the filing date to audit a return, or six years if substantial income is omitted. About 0.4% of returns are audited.
filingItemized Deductions
Specific expenses you can deduct from your AGI instead of taking the standard deduction. Common itemized deductions include state and local taxes (SALT, capped at $10,000), mortgage interest, charitable contributions, and medical expenses exceeding 7.5% of AGI. You should itemize only if your total itemized deductions exceed the standard deduction for your filing status.
deductionsK
Kiddie Tax
A tax rule that applies the parent's marginal tax rate to a child's unearned income (interest, dividends, capital gains) above a threshold. For 2025, the first $1,300 of a child's unearned income is tax-free, the next $1,300 is taxed at the child's rate, and amounts above $2,600 are taxed at the parent's rate. The rule applies to children under 19 (or under 24 if a full-time student) who do not provide more than half their own support.
tax-typesKindergeld (German Child Benefit)
A monthly child benefit payment in Germany of €250 per child, regardless of income. It's paid from birth until the child turns 18 (or 25 if in education/training). Kindergeld is typically paid to one parent and is technically an advance on the child tax allowance (Kinderfreibetrag). The tax office automatically checks whether the allowance or Kindergeld is more beneficial during your annual tax assessment.
internationalKirchensteuer (German Church Tax)
A tax collected by the German government on behalf of recognized religious communities (primarily Catholic and Protestant churches). The rate is 8% of income tax in Bavaria and Baden-Württemberg, and 9% in all other German states. It's automatically deducted from your salary if you're registered as a member of a participating church. You can opt out by formally leaving your church at the local civil court (Amtsgericht).
internationalM
Marginal Tax Rate
The tax rate applied to your last dollar of taxable income. The US uses a progressive tax system with seven brackets: 10%, 12%, 22%, 24%, 32%, 35%, and 37%. Each bracket applies only to income within that range, not your entire income. Your effective (average) tax rate is always lower than your marginal rate.
tax-typesMedical Expense Deduction
An itemized deduction for unreimbursed medical and dental expenses that exceed 7.5% of your AGI. Qualifying expenses include doctor visits, prescriptions, health insurance premiums (if not pre-tax), dental work, vision care, mental health services, and certain travel costs for medical care. Cosmetic procedures generally don't qualify unless medically necessary.
deductionsModified Adjusted Gross Income (MAGI)
Your Adjusted Gross Income (AGI) with certain deductions added back in, such as student loan interest, IRA contributions, and foreign earned income exclusion. MAGI is used to determine eligibility for Roth IRA contributions, premium tax credits under the ACA, education credits, and the deductibility of traditional IRA contributions. The specific add-backs vary depending on which tax benefit is being evaluated.
incomeMortgage Interest Deduction
An itemized deduction that allows homeowners to deduct interest paid on mortgage loans for their primary residence and one additional home. For mortgages taken out after December 15, 2017, the deduction is limited to interest on the first $750,000 of mortgage debt ($375,000 for married filing separately). Interest on home equity loans is deductible only if the funds are used to buy, build, or substantially improve the home.
deductionsN
National Insurance (UK)
A UK tax on earnings and self-employment profits that funds state benefits including the State Pension, unemployment benefits, and the National Health Service. Employees pay 8% on earnings between £12,570 and £50,270, and 2% above that. Employers pay 13.8% on employee earnings above £9,100. Self-employed pay Class 2 (flat rate) and Class 4 (6% on profits between £12,570 and £50,270).
internationalNet Income
Your income after all deductions, exemptions, and taxes have been subtracted. In a business context, net income is revenue minus all expenses, taxes, and costs. On a personal level, it's your take-home pay after all withholdings. Net income is different from AGI and taxable income—it represents what you actually keep.
incomeNet Investment Income Tax (NIIT)
An additional 3.8% tax on investment income for high earners. It applies to the lesser of net investment income or the amount by which MAGI exceeds $200,000 (single) or $250,000 (married filing jointly). Investment income includes interest, dividends, capital gains, rental income, royalties, and passive activity income. It does not apply to wages, self-employment income, Social Security benefits, or tax-exempt interest.
tax-typesP
Partnership
A business structure where two or more individuals share ownership and operate a business together. Partnerships file an information return (Form 1065) but do not pay income tax at the entity level. Instead, each partner receives a Schedule K-1 reporting their share of income, deductions, and credits. General partners pay self-employment tax on their distributive share, while limited partners generally do not. Partnership agreements determine how profits and losses are allocated among partners.
businessPass-Through Income
Business income that "passes through" to the owner's personal tax return rather than being taxed at the corporate level. Sole proprietorships, partnerships, S corporations, and LLCs are common pass-through entities. The Tax Cuts and Jobs Act introduced a 20% qualified business income (QBI) deduction for many pass-through income earners, subject to income and business type limitations.
businessPAYE (Pay As You Earn)
The UK system where employers deduct income tax and National Insurance contributions directly from employees' wages before paying them. Similar to US withholding but more comprehensive—most UK employees never need to file a tax return because PAYE handles their entire tax obligation. HM Revenue & Customs (HMRC) assigns a tax code to each employee that determines the correct amount to deduct.
internationalPayroll Tax
Taxes withheld from employee wages and paid by both employers and employees to fund Social Security and Medicare (collectively known as FICA). Employees pay 6.2% for Social Security (on wages up to $176,100 in 2025) and 1.45% for Medicare (no wage cap), for a combined 7.65%. Employers match these amounts. An additional 0.9% Medicare surtax applies to wages over $200,000 for single filers. Payroll taxes are separate from income tax.
tax-typesPremium Tax Credit
A refundable tax credit that helps eligible individuals and families afford health insurance purchased through the Health Insurance Marketplace. The credit is based on household income relative to the federal poverty level and the cost of the benchmark (second-lowest-cost silver) plan in your area. It can be taken in advance to lower monthly premiums or claimed when filing your tax return. You must reconcile advance payments on Form 8962. Income changes during the year can affect the final credit amount.
creditsQ
Qualified Business Income (QBI) Deduction
Also known as the Section 199A deduction, it allows eligible self-employed individuals and small business owners to deduct up to 20% of their qualified business income from pass-through entities (sole proprietorships, partnerships, S corps). The deduction is limited for specified service trades or businesses (law, medicine, consulting, etc.) when taxable income exceeds $191,950 (single) or $383,900 (joint) in 2025. The deduction is taken on your personal return and reduces taxable income but not AGI.
businessQuarterly Estimated Taxes
Tax payments made four times a year by individuals who don't have enough tax withheld from their income. This typically applies to self-employed individuals, freelancers, investors, and retirees. Payments are due April 15, June 15, September 15, and January 15. Failing to make estimated payments can result in an underpayment penalty.
filingQuotient Familial (French Family Quotient)
France's unique tax calculation method that divides household income by a number of "parts" based on family size. A single person counts as 1 part, a married couple as 2 parts, each of the first two children adds 0.5 parts, and additional children add 1 part each. The progressive tax rates are applied to the per-part income, then multiplied back by the number of parts. This system significantly benefits larger families.
internationalR
Refundable Tax Credit
A tax credit that can reduce your tax liability below zero, resulting in a refund. Even if you owe no taxes, you can receive the credit as a payment. Key refundable credits include the Earned Income Tax Credit, the refundable portion of the Child Tax Credit, and the American Opportunity Credit (40% refundable up to $1,000).
creditsRequired Minimum Distribution (RMD)
The minimum amount you must withdraw annually from tax-deferred retirement accounts (traditional IRAs, 401(k)s, 403(b)s) starting at age 73 (as of 2023). RMDs are calculated by dividing your account balance as of December 31 of the prior year by an IRS life expectancy factor. Failure to take RMDs results in a 25% excise tax on the amount not withdrawn (reduced to 10% if corrected within two years). Roth IRAs are exempt from RMDs during the owner's lifetime.
retirementRoth 401(k)
An employer-sponsored retirement account that combines features of a traditional 401(k) and a Roth IRA. Contributions are made with after-tax dollars (no upfront tax deduction), but qualified withdrawals in retirement are completely tax-free. The 2025 contribution limit is $23,500 ($31,000 if age 50 or older). Unlike Roth IRAs, Roth 401(k)s have no income limit for contributions. Starting in 2024, Roth 401(k)s are no longer subject to required minimum distributions (RMDs).
retirementRoth IRA
An individual retirement account funded with after-tax dollars. Contributions are not deductible, but qualified withdrawals in retirement are completely tax-free—including all investment gains. For 2025, the contribution limit is $7,000 ($8,000 if age 50+). Income limits apply: single filers with MAGI above $161,000 face reduced limits, and those above $176,000 cannot contribute directly.
retirementS
S Corporation
A corporation that elects pass-through tax treatment under Subchapter S of the Internal Revenue Code. S corps avoid double taxation by passing income, losses, deductions, and credits through to shareholders' personal tax returns. Owner-employees must pay themselves a "reasonable salary" subject to payroll taxes, but remaining profits distributed as dividends are not subject to self-employment tax. S corps are limited to 100 shareholders and can only issue one class of stock.
businessSALT Deduction (State and Local Taxes)
An itemized deduction for state and local taxes paid, including state income taxes (or sales taxes) and property taxes. The Tax Cuts and Jobs Act of 2017 capped this deduction at $10,000 ($5,000 for married filing separately) through 2025. This cap particularly affects taxpayers in high-tax states like New York, California, and New Jersey.
deductionsSchedule C
IRS Form 1040 Schedule C, used to report profit or loss from a business you operated as a sole proprietor. It calculates your net business income by subtracting business expenses from business revenue. The resulting profit is subject to both income tax and self-employment tax. Common expenses include home office, supplies, travel, insurance, and vehicle costs.
formsSchedule E
An IRS form (supplement to Form 1040) used to report income or loss from rental real estate, royalties, partnerships, S corporations, estates, and trusts. Rental income and expenses are reported in Part I, while pass-through income from partnerships and S corporations (reported on K-1 forms) goes in Part II. Net income from Schedule E flows to your Form 1040 and is generally not subject to self-employment tax.
formsSchedule K-1
A tax form issued by partnerships, S corporations, estates, and trusts to report each partner, shareholder, or beneficiary's share of income, deductions, and credits. K-1 income is "pass-through" income, meaning the entity itself does not pay tax; instead, the income is reported on each recipient's individual tax return. Partnership K-1s come from Form 1065, S corporation K-1s from Form 1120-S, and trust/estate K-1s from Form 1041.
formsSelf Assessment (UK)
The UK system where individuals report their income and calculate their own tax liability by filing a tax return with HMRC. Most employees don't need to file because PAYE covers their taxes, but self-assessment is required for self-employed individuals, those with income over £150,000, company directors, and those with significant investment income, rental income, or foreign income. The deadline for online filing is January 31 following the end of the tax year (April 5).
internationalSelf-Employment Tax
The Social Security and Medicare tax paid by self-employed individuals. Since self-employed people are both employer and employee, they pay the full 15.3% (12.4% Social Security + 2.9% Medicare) on net earnings. You can deduct half of self-employment tax as an adjustment to income. The tax applies to net self-employment income of $400 or more.
tax-typesSole Proprietorship
The simplest business structure, where an individual operates a business without forming a separate legal entity. All income and expenses are reported on Schedule C of your personal tax return. Net profit is subject to both income tax and self-employment tax (15.3%). There is no legal separation between you and the business, meaning personal assets are at risk for business debts. Most freelancers, gig workers, and independent contractors are sole proprietors by default.
businessSolidaritätszuschlag (German Solidarity Surcharge)
A supplementary tax in Germany originally introduced to fund the costs of German reunification. It's calculated as 5.5% of your income tax liability. Since 2021, most taxpayers are exempt—only those with income tax exceeding approximately €18,130 (single) or €36,260 (married) pay it. This effectively limits it to higher earners.
internationalStandard Deduction
A fixed dollar amount that reduces your taxable income, available to all taxpayers who don't itemize. For 2025, the standard deduction is $15,000 for single filers, $30,000 for married filing jointly, and $22,500 for head of household. Taxpayers age 65 or older or who are blind receive additional standard deduction amounts. About 90% of taxpayers take the standard deduction.
deductionsStudent Loan Interest Deduction
An above-the-line deduction of up to $2,500 for interest paid on qualified student loans. You can claim this deduction even if you don't itemize. The deduction phases out at MAGI between $80,000 and $95,000 ($165,000 and $195,000 for joint filers). To qualify, the loan must have been taken out solely to pay qualified education expenses, and you can't be claimed as a dependent on someone else's return.
deductionsT
Tax Bracket
A range of income taxed at a specific rate in the progressive US tax system. For 2025, there are seven federal income tax brackets: 10% ($0–$11,600 for single), 12% ($11,601–$47,150), 22% ($47,151–$100,525), 24% ($100,526–$191,950), 32% ($191,951–$243,725), 35% ($243,726–$609,350), and 37% (over $609,350). Only the income within each bracket is taxed at that rate.
tax-typesTax Credit
A dollar-for-dollar reduction in the amount of tax you owe, more valuable than a deduction. Tax credits can be nonrefundable (reducing your tax to zero but no further) or refundable (you receive the excess as a refund). Common credits include the Child Tax Credit, Earned Income Credit, American Opportunity Credit, and Lifetime Learning Credit.
creditsTax Deduction
An expense that you can subtract from your taxable income, reducing the amount of income subject to tax. Deductions come in two forms: the standard deduction (a fixed amount based on filing status) and itemized deductions (specific expenses like mortgage interest, state taxes, and charitable donations). Unlike tax credits, deductions reduce your taxable income, not your tax bill directly.
deductionsTax Exemption
An amount of income that is not subject to taxation. Personal exemptions were eliminated by the Tax Cuts and Jobs Act of 2017 for tax years 2018–2025, but the concept still applies in other contexts. Certain types of income are exempt from tax, such as municipal bond interest, gifts below the annual exclusion amount ($18,000 in 2025), and some employer benefits like health insurance.
deductionsTax Extension (Form 4868)
A request for additional time to file your tax return, giving you until October 15 instead of April 15. Form 4868 grants an automatic 6-month extension to file—but not to pay. You must still estimate and pay any taxes owed by the original deadline to avoid penalties and interest. About 10-15 million taxpayers file extensions each year.
filingTax Liability
The total amount of tax you owe to a taxing authority for a given period. Your federal tax liability is calculated by applying tax rates to your taxable income, then subtracting credits. It is different from the amount you owe when you file: if your withholding and estimated payments exceed your liability, you get a refund. If they fall short, you owe the balance. Tax liability includes income tax, self-employment tax, AMT, and any additional taxes.
filingTax Refund
Money returned to you by the IRS when you've paid more in taxes during the year than you actually owe. Refunds typically result from excess withholding from paychecks or refundable tax credits. The average federal tax refund is approximately $3,100. While getting a refund feels good, it actually means you gave the government an interest-free loan throughout the year.
filingTax Treaty
A bilateral agreement between two countries that determines how income earned by residents of one country in the other is taxed. Tax treaties prevent double taxation, reduce withholding rates on dividends, interest, and royalties, and establish rules for which country has the primary right to tax certain types of income. The U.S. has tax treaties with over 60 countries. Treaty benefits must be claimed on your tax return; they are not applied automatically.
internationalTax Withholding
The amount of federal income tax your employer deducts from your paycheck and sends directly to the IRS on your behalf. Withholding is based on the information you provide on Form W-4. If too much is withheld, you get a refund; if too little, you owe taxes when you file. Self-employed individuals handle this through quarterly estimated tax payments instead.
filingTax Withholding
The portion of your paycheck that your employer sends directly to the IRS as a prepayment of your income tax. The amount withheld is based on the information you provide on Form W-4, including filing status, dependents, and additional withholding requests. Proper withholding should closely match your actual tax liability to avoid a large balance due or an excessive refund. You can adjust your W-4 at any time during the year.
filingTax-Loss Harvesting
An investment strategy that involves selling securities at a loss to offset capital gains and reduce taxable income. After selling, investors typically purchase a similar (but not "substantially identical") investment to maintain their portfolio allocation while capturing the tax benefit. Up to $3,000 in net losses can offset ordinary income annually, with excess losses carried forward. The wash sale rule must be observed to ensure the loss is deductible.
incomeTaxable Income
Your adjusted gross income minus either the standard deduction or itemized deductions. This is the actual amount of income subject to federal income tax. Tax brackets and rates are applied to your taxable income, not your gross income or AGI.
incomeTraditional IRA
An individual retirement account where contributions may be tax-deductible, reducing your current taxable income. Investment gains grow tax-deferred until withdrawal in retirement, when they're taxed as ordinary income. The 2025 contribution limit is $7,000 ($8,000 if age 50+). Deductibility depends on your income and whether you're covered by an employer retirement plan.
retirementTrust
A legal arrangement in which a trustee holds and manages assets on behalf of beneficiaries. For tax purposes, trusts are either grantor trusts (where income is taxed to the creator) or non-grantor trusts (which are separate tax entities filing Form 1041). Common types include revocable living trusts, irrevocable trusts, charitable remainder trusts, and special needs trusts. Trusts reach the highest tax bracket (37%) at just $15,200 of income in 2025, making distributions to beneficiaries a common tax strategy.
businessW
W-2 Form
The wage and tax statement your employer is required to send you by January 31 each year. It reports your total wages, tips, and compensation, along with federal and state taxes withheld, Social Security and Medicare taxes, and other information needed to file your return. You'll receive a W-2 from each employer you worked for during the year.
formsW-4 Form
The Employee's Withholding Certificate you fill out when starting a new job (or anytime you want to adjust withholding). It tells your employer how much federal income tax to withhold from each paycheck. The current W-4 (redesigned in 2020) uses a five-step process instead of the old allowance system.
formsWash Sale Rule
An IRS rule that disallows a tax deduction for a capital loss if you purchase a "substantially identical" security within 30 days before or after the sale. The disallowed loss is added to the cost basis of the replacement security, deferring (not eliminating) the tax benefit. The rule applies to stocks, bonds, mutual funds, ETFs, and options. It does not currently apply to cryptocurrency, though legislation has been proposed to close this gap.
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