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Income Taxation: Home

Income Tax research guide for law students and other researchers

Useful Definitions

Dependent: A person, such as a child or parent, for whom a taxpayer may be able to claim a personal exemption if the taxpayer provides more than half of the person's support during the taxable year.

W-4 Form: A form indicating the number of personal exemptions an employee is claiming and that is used by the employer in determining the amount of income to be withheld from the employee's paycheck for federal-income tax purposes.

Income Tax: A tax on an individual's or entity's net income.

Internal Revenue Service (IRS): A unit in the U.S. Department of the Treasury responsible for enforcing and administering the internal-revenue laws and other tax laws except those relating to alcohol, tobacco, firearms, and explosives.

Sales TaxA tax imposed on the sale of goods and services, usually measured as a percentage of their price.

Tax DeductionAn amount subtracted from gross income when calculating adjusted gross income, or from adjusted gross income when calculating taxable income.

All definitions come from Black’s Law Dictionary (11th ed. 2019).


Taxation is the process whereby charges are imposed on individuals or property by the legislative branch of the federal government and by many state governments to raise funds for public purposes.

The theory that underlies taxation is that charges are imposed to support the government in exchange for the general advantages and protection afforded by the government to the taxpayer and his or her property. The existence of government is a necessity that cannot continue without financial means to pay its expenses; therefore, the government has the right to compel all citizens and property within its limits to share its costs. The state and federal governments both have the power to impose taxes upon their citizens.

[Summary from Taxation,, (last visited 11/03/2015).

Subscripiton Databases

Bloomberg Law: Under the Practice Centers tab, the Tax link provides thirteen types of sources (including current awareness resources from BNA Law Reports), a News & Analysis section, audio and video files addressing business news, and a search feature.

Lexis Advance: Browse Sources—Secondary Materials—Texas—Texas Tax Practice Insights

Browse Sources—Secondary Materials—U.S. Federal—Federal Tax Practice and Procedure

Browse Topics—Tax Law

Westlaw: Under Browse—Topics—Tax, various resources are listed including Regulations, Secondary Sources, Forms, and Proposed & Enacted Legislation.

Under Tools—West Key Number System, 220: Internal Revenue and 371: Taxation may provide guidance in finding related materials.

Subject Guide

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