Editing Taxation in the United States (section)

===Federal===

====Internal Revenue Service====
{{Main|Internal Revenue Service}}

The Internal Revenue Service administers all U.S. federal tax laws on domestic activities, except those taxes administered by TTB. IRS functions include:
* Processing federal tax returns (except TTB returns), including those for Social Security and other federal payroll taxes
* Providing assistance to taxpayers in completing tax returns
* Collecting all taxes due related to such returns
* Enforcement of tax laws through examination of returns and assessment of penalties
* Providing an appeals mechanism for federal tax disputes
* Referring matters to the Justice Department for prosecution
* Publishing information about U.S. federal taxes, including forms, publications, and other materials
* Providing written guidance in the form of rulings binding on the IRS for the public and for particular taxpayers

The IRS maintains several Service Centers at which tax returns are processed. Taxpayers generally file<ref>{{Cite web |url=https://www.irs.gov/file/article/0,,id=111453,00.html |title=Where to File Tax Returns - Addresses Listed by Return Type |access-date=2017-08-10 |archive-date=2012-08-24 |archive-url=https://web.archive.org/web/20120824163249/http://www.irs.gov/file/article/0,,id=111453,00.html |url-status=dead }}</ref> most types of tax returns by mail with these Service Centers, or file electronically. The IRS also maintains a National Office in Washington, DC, and numerous local offices<ref>{{Cite web |url=https://www.irs.gov/localcontacts/index.html |title=Contact Your Local IRS Office |access-date=2017-08-10 |archive-date=2012-08-27 |archive-url=https://web.archive.org/web/20120827122406/http://www.irs.gov/localcontacts/index.html |url-status=dead}}</ref> providing taxpayer services and administering tax examinations.

=====Examination=====
Tax returns filed with the IRS are subject to examination<ref>{{cite web |url=https://www.irs.gov/publications/p556/index.html |title=Publication 556 (09/2013), Examination of Returns, Appeal Rights, and Claims for Refund &#124; Internal Revenue Service}}</ref> and adjustment, commonly called an IRS audit. Only a small percentage of returns (about 1% of individual returns in IRS FY 2008)<ref>{{cite web|url=https://www.irs.gov/pub/irs-soi/08db09bex.xls|title=Examination Coverage: Individual Income Tax Returns Examined, by Size of Adjusted Gross Income, Fiscal Year 2008|format=XLS|access-date=December 20, 2023}}</ref> are examined each year. The selection of returns uses a variety of methods based on IRS experiences. On examination, the IRS may request additional information from the taxpayer by mail, in person at IRS local offices, or at the business location of the taxpayer. The taxpayer is entitled to representation by an [[Attorneys in the United States|attorney]], [[Certified Public Accountant]] (CPA), or [[enrolled agent]], at the expense of the taxpayer, who may make representations to the IRS on behalf of the taxpayer.

Taxpayers have certain rights in an audit. Upon conclusion of the audit, the IRS may accept the tax return as filed or propose adjustments<ref>{{Cite web |url=https://www.irs.gov/businesses/article/0,,id=180776,00.html |title=Notice of Proposed Adjustment |access-date=2017-08-10 |archive-date=2008-05-11 |archive-url=https://web.archive.org/web/20080511051026/http://www.irs.gov/businesses/article/0,,id=180776,00.html |url-status=dead}}</ref> to the return. The IRS may also assess [[IRS penalties|penalties]] and interest. Generally, adjustments must be proposed within three years<ref>{{cite web | url=https://www.law.cornell.edu/uscode/text/26/6501 | title=26 U.S. Code § 6501 - Limitations on assessment and collection }}</ref> of the due date of the tax return. Certain circumstances extend this time limit, including substantial understatement of income and fraud. The taxpayer and the IRS may agree<ref>{{cite web|url=https://www.irs.gov/pub/irs-tege/form872.pdf|title=Consent to Extend the Time to Assess Tax|work=Form 872|publisher=[[United States Department of the Treasury|Department of the Treasury]]-[[Internal Revenue Service]]|date=December 2004|url-status=dead|archive-url=https://web.archive.org/web/20190412082942/https://www.irs.gov/pub/irs-tege/form872.pdf|archive-date=April 12, 2019|access-date=December 20, 2023}}</ref> to allow the IRS additional time to conclude an audit. If the IRS proposes adjustments, the taxpayer may agree to the adjustment, [[Office of Appeals|appeal within the IRS]], or seek judicial determination of the tax.

=====Published and private rulings=====
In addition to enforcing tax laws, the IRS provides formal and informal guidance to taxpayers. While often referred to as IRS Regulations, the regulations under the Internal Revenue Code are issued by the Department of Treasury. IRS guidance consists of:

* [[Revenue Ruling]]s, Revenue Procedures, and various IRS pronouncements applicable to all taxpayers and published in the [[Internal Revenue Bulletin]],<ref>{{cite web|title=Internal Revenue Bulletin: 2012-23|url=https://www.irs.gov/irb/2012-23_IRB/ar08.html|publisher=Internal Revenue Service|access-date=June 7, 2012|date=June 4, 2012}}</ref> which are binding on the IRS
* [[Private letter ruling]]s on specific issues, applicable only to the taxpayer who applied for the ruling
* IRS Publications providing informal instruction to the public on tax matters<ref>{{Cite web |url=https://www.irs.gov/formspubs/article/0,,id=98171,00.html |title=Topical Index to Forms, Instructions and Publications-A |access-date=2017-08-10 |archive-date=2011-06-22 |archive-url=https://web.archive.org/web/20110622034530/http://www.irs.gov/formspubs/article/0,,id=98171,00.html |url-status=dead}}</ref> 
* IRS forms and instructions<ref>{{cite web |url=https://www.irs.gov/app/picklist/list/formsInstructions.html |title=Forms, Instructions and Publications &#124; Internal Revenue Service}}</ref>
* A comprehensive web site<ref>{{cite web|url=https://www.irs.gov |title=Internal Revenue Service &#124; An official website of the United States government |publisher=Irs.gov |date= |access-date=2022-08-25}}</ref> 
* Informal (nonbinding) advice by telephone

====Alcohol and Tobacco Tax and Trade Bureau====
{{Main|Alcohol and Tobacco Tax and Trade Bureau}}

The Alcohol and Tobacco Tax Trade Bureau (TTB), a division of the [[United States Department of the Treasury|Department of the Treasury]], enforces federal excise tax laws related to alcohol, tobacco, and firearms. TTB has six divisions, each with discrete functions:

* Revenue Center: processes tax returns and issues permits, and related activities
* Risk Management: internally develops guidelines and monitors programs
* Tax Audit: verifies filing and payment of taxes
* Trade Investigations: investigating arm for non-tobacco items
* Tobacco Enforcement Division: enforcement actions for tobacco
* Advertising, Labeling, and Formulation Division: implements various labeling and ingredient monitoring

Criminal enforcement related to TTB is done by the [[Bureau of Alcohol, Tobacco, Firearms, and Explosives]], a division of the [[United States Department of Justice|Justice Department]].

====Customs and Border Protection====
{{Main|U.S. Customs and Border Protection}}

U.S. Customs and Border Protection (CBP), an agency of the [[United States Department of Homeland Security]], collects customs duties and regulates international trade. It has a workforce of over 58,000 employees covering over 300 official ports of entry to the United States. CBP has authority to seize and dispose of cargo in the case of certain violations of customs rules.