Title 26 › Subtitle A — Income Taxes › CHAPTER 1 — NORMAL TAXES AND SURTAXES › Subchapter E — Accounting Periods and Methods of Accounting › PART I — ACCOUNTING PERIODS › § 441
Taxable income is figured for whatever the taxpayer’s taxable year is. The taxable year can be the taxpayer’s regular annual accounting period (either a calendar year or a fiscal year), the calendar year when the taxpayer has no proper accounting period or books, the short period the return covers if it is less than 12 months, or a special period for certain DISC corporations tied to their main shareholder. Annual accounting period means the yearly period the taxpayer normally uses in their books. Calendar year means 12 months ending on December 31. Fiscal year means 12 months ending on the last day of any month except December (or an elected annual period that varies from 52 to 53 weeks). A taxpayer who keeps books on a 52–53 week year that always ends the same weekday and meets the timing rules may elect to use that year. When a 52–53 week year is used for dates tied to the first or last day of a month, it is treated as beginning or ending with the nearest calendar month. If switching years creates a short tax period, special rules apply: if the short period is 359 days or more or under 7 days, one alternative computation rule does not apply; if under 7 days it is added to the next year; and when annualizing a short period for tax, income is multiplied by 365 and divided by the number of days in the short period. The Secretary can make rules for partnerships, S corporations, and personal service corporations. For DISC rules, a DISC uses the taxable year of the shareholder (or shareholder group) with the largest voting power; ties use any tied shareholder’s year; later ownership changes affect this only if ownership changes substantially. Personal service corporations must use the calendar year unless they show a real business reason for a different year, and shifting income to shareholders is not a valid business reason. A personal service corporation is defined by who owns its stock, including a rule that more than 10 percent of the stock (by value) must be held by employee-owners, with affiliated group members counted too.
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Internal Revenue Code, Source: USLM XML via OLRC
Legislative History
Reference
Citation
26 U.S.C. § 441
Title 26, Internal Revenue Code
Last Updated
Sep 22, 2026
Release point: 119-110