Internal Revenue Service | Internal Revenue Service
1111 Constitution Ave NW, Washington, DC 20224-0001
All taxpayers, including small business owners and sole proprietors
Mon-Fri 7am-7pm local time by phone
Toll-Free TTY
Toll-Free for Businesses
Toll-Free for Individuals
Call or visit website
None for information
AZ
Federal tax collection agency administers the Internal Revenue Code enacted by Congress. Provides information by phone and online to help people understand and meet their tax responsibilities. Website provides forms which can be downloaded, and information about tax return corrections, penalties and penalty relief, refunds, deductions, and credits (Earned Income Tax Credit, education, child care, adoption, Saver's Credit, Welfare-to-Work, and Work Opportunity Tax Credit). Also provides answers to frequently asked questions for individuals, businesses, and nonprofits.
10/01/2025
Internal Revenue Service
Federal tax collection agency administers the Internal Revenue Code enacted by Congress. Provides information by phone and online to help people understand and meet their tax responsibilities. Website provides forms which can be downloaded, and information about tax return corrections, penalties and penalty relief, refunds, deductions, and credits (Earned Income Tax Credit, education, child care, adoption, Saver's Credit, Welfare-to-Work, and Work Opportunity Tax Credit). Also provides answers to frequently asked questions for individuals, businesses, and nonprofits.