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Glossary/Tax and regulatory

Circular 230

Circular 230, codified at 31 CFR Part 10, is the Treasury regulation governing practice before the IRS, setting duties of diligence, return standards, and sanctions for CPAs, attorneys, enrolled agents, and others.

CORAA TeamUpdated November 5, 2026

Definition

Circular 230 is the name for 31 CFR Part 10, Regulations Governing Practice before the Internal Revenue Service. Practice before the IRS covers preparing and filing documents, corresponding with the IRS, and representing taxpayers at conferences and hearings. Subpart B sets duties and restrictions, including due diligence on the accuracy of submissions, standards for tax returns and documents, and competence. Subpart C covers sanctions, including censure, suspension, disbarment, and monetary penalties, and the Office of Professional Responsibility enforces it.

Why it matters in an audit or review

CPAs, attorneys, and enrolled agents are practitioners under the rules. For audit firms that also prepare tax returns or provide tax advice to attest clients, Circular 230 adds obligations separate from the AICPA Code and state board rules, and a violation can end in IRS sanctions even if the state license is unaffected. Firms keep written procedures for these duties.

Example

Illustrative: a preparer signs a return using client numbers that look inconsistent with last year's return without asking questions. Circular 230 (section 10.34(d)) lets a practitioner rely in good faith on client information but expects reasonable inquiry when it appears incorrect, inconsistent or incomplete.

Common mistakes

Believing a state license replaces compliance with federal practice rules.

FAQ

Who enforces Circular 230?

The IRS Office of Professional Responsibility.

Sources

Definitions paraphrase AICPA and FASB guidance; read the standard itself before relying on a requirement. Example figures are illustrative. This page is guidance, not professional advice. Report an error

Standards

31 CFR Part 10

Related terms

  • Enrolled agent (EA)
    An enrolled agent is a federally authorized tax practitioner who passed the IRS Special Enrollment Examination or qualified through IRS experience and may represent taxpayers before the IRS in any state.
  • PTIN (Preparer Tax Identification Number)
    A PTIN is the IRS number that anyone paid to prepare all or substantially all of a federal tax return must obtain, renew each year, and put on the returns they prepare.
  • Section 7216 (tax return preparer disclosure)
    Section 7216 of the Internal Revenue Code makes it a misdemeanor for a tax return preparer to knowingly or recklessly disclose or use return information beyond preparing the return, with limited exceptions.
  • CPA (Certified Public Accountant)
    A CPA is an accountant licensed by a US state board of accountancy after meeting education, examination, experience, and ethics requirements; only licensees may issue audit and review reports in most states.

Go deeper

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