Internal Revenue Code (IRC): The primary source of federal tax law in the United States, codified in Title 26 of the United States Code, which provides the foundation for federal taxation
Tax Cuts and Jobs Act of 2017: Major tax reform legislation that significantly modified the IRC, affecting both individual and corporate taxation
Federal Tax Regulations: Treasury Regulations that provide detailed interpretations and guidelines for implementing the Internal Revenue Code
IRS Revenue Rulings: Official interpretations by the IRS of the tax laws, applying tax law to specific factual situations
IRS Revenue Procedures: Official statements of practice and procedures that affect the rights and duties of taxpayers and the general public
IRS Private Letter Rulings: Written statements issued to taxpayers that interpret and apply tax laws to specific sets of facts, though only binding for the requesting taxpayer
Foreign Account Tax Compliance Act (FATCA): Legislation requiring foreign financial institutions to report on foreign assets held by U.S. account holders
Tax Treaties: Bilateral agreements between the United States and other countries that help prevent double taxation and establish rules for tax treatment of cross-border activities
BEPS Guidelines: Base Erosion and Profit Shifting guidelines addressing tax avoidance strategies that exploit gaps in tax rules to artificially shift profits
State Tax Codes: Individual state legislation governing taxation at the state level, which varies by jurisdiction
Commerce Clause: Constitutional provision that affects states' ability to tax interstate commerce and international trade
Due Process Clause: Constitutional requirement ensuring fair and reasonable application of tax laws and procedures
Supremacy Clause: Constitutional provision establishing federal tax law precedence over conflicting state laws
Administrative Procedure Act: Federal statute governing how administrative agencies propose and establish regulations, including tax regulations
Taxpayer Bill of Rights: Fundamental rights taxpayers have in dealing with the IRS, including the right to be informed and the right to appeal
Taxpayer First Act: Legislation aimed at reforming the IRS to improve taxpayer service and enforcement procedures
