### Question
How does the law define annual accounting period?


### Answer
Under *26 U.S.C. § 441*, **annual accounting period** is defined as:

> the annual period on the basis of which the taxpayer regularly computes his income in keeping his books

#### Citation:
  - *26 U.S.C. § 441*
  - Heading: **Subtitle A-Income Taxes > CHAPTER 1-NORMAL TAXES AND SURTAXES > Subchapter E-Accounting Periods and Methods of Accounting > PART I-ACCOUNTING PERIODS**

