Circular 230 is the common term for Title 31 Code of Federal Regulations, Subtitle A, Part 10. Circular 230 provides the rules governing practice before the Internal Revenue Service. This regulation explains, and expands on, Title 31 USC §330. This section is what gives the Secretary of the Treasury the authority to regulate those who practice before the IRS.

§330 (a) Subject to section 500 of title 5, the Secretary of the Treasury may—

1. regulate the practice of representatives of persons before the Department of
   the Treasury; and
2. before admitting a representative to practice, require that the representative demonstrate—
   1. good character;
   2. good reputation;
   3. necessary qualifications to enable the representative to provide to persons valuable service; and
   4. competency to advise and assist persons in presenting their cases.

Treasury Department has unsuccessfully attempted to regulate individuals and firms who prepare tax returns. In 2011 the IRS published regulations that were meant to protect consumers by regulating the tax preparation industry. The regulations were met with resistance, leading to class action suits against the IRS. A district court found in Loving, 920 F.Supp.2d 108 (D.D.C. 2013), aff’d 742 F.3d 103 (D.C. Cir. 2014) that the IRS did not have authority to regulate all preparers of income tax returns. The original regulations provided for required registration of all preparers and imposed continuing education requirements on all registrants. The Court found that the preparation of tax returns was not practice before the IRS. After the Loving decision the IRS backtracked by creating the Annual Filing Season Program. Participating in the program is voluntary. However, an individual who participates in the program consents to adhere to the practice requirements of Circular 230.

The most recent revision to Circular 230 was the publication of final regulations on June 12, 2014.