Editing Taxation in the United States (section)

===Reporting under self-assessment system===
{{Main|Tax return (United States)}}

Income taxes in the United States are self-assessed by taxpayers<ref>{{USCSub|26|6201|a|1}}; IRS [ Publication ].</ref> by filing required tax returns.<ref>{{USC|26|6011}}.</ref> Taxpayers, as well as certain non-tax-paying entities, like partnerships, must file annual [[Tax return (United States)|tax returns]] at the federal and applicable state levels. These returns disclose a complete computation of taxable income under tax principles. Taxpayers compute all income, deductions, and credits themselves, and determine the amount of tax due after applying required prepayments and taxes withheld. Federal and state tax authorities provide preprinted forms that must be used to file tax returns. IRS [[IRS tax forms#1098 series|Form 1040 series]] is required for individuals, Form [[IRS tax forms#1120_series|1120 series]] for corporations, Form [[IRS tax forms#Entity_returns|1065]] for partnerships, and Form [[IRS tax forms#990|990 series]] for tax exempt organizations.

The state forms vary widely, and rarely correspond to federal forms. Tax returns vary from the two-page (Form 1040EZ)<ref>{{cite web | url=https://www.irs.gov/pub/irs-pdf/f1040ez.pdf | title=About Form 1040-EZ, Income Tax Return for Single and Joint Filers with No Dependents &#124; Internal Revenue Service }}</ref>  used by nearly 70% of individual filers to thousands of pages of forms and attachments for large entities. Groups of corporations may elect to file [[Combined reporting#United States consolidated returns|consolidated returns]] at the federal level and with a few states. Electronic filing of federal<ref>{{Cite web |url=https://www.irs.gov/efile/index.html |title=Information for e-file |access-date=2017-08-10 |archive-date=2012-08-29 |archive-url=https://web.archive.org/web/20120829121841/http://www.irs.gov/efile/index.html |url-status=dead }}</ref> and many state returns is widely encouraged and in some cases required, and many vendors offer computer software for use by taxpayers and paid return preparers to prepare and electronically file returns.