# 31 C.F.R. § 10.21 (2026): Knowledge of client's omission

> Federal · Regulations · In force

URL: https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_21

## Section

- **Citation:** 31 C.F.R. § 10.21 (2026)
- **Heading:** Knowledge of client's omission
- **Jurisdiction:** Federal
- **Kind:** Regulations
- **Status:** In force
- **Text as of:** August 14, 2026
- **Source:** Compiled text
- **Location:** Title 31 CFR: Money and Finance: Treasury / Part 10: PRACTICE BEFORE THE INTERNAL REVENUE SERVICE / Subpart B: Duties and Restrictions Relating to Practice Before the Internal Revenue Service / § 10.21: § 10.21   Knowledge of client's omission.

## Text

A practitioner who, having been retained by a client with respect to a matter administered by the Internal Revenue Service, knows that the client has not complied with the revenue laws of the United States or has made an error in or omission from any return, document, affidavit, or other paper which the client submitted or executed under the revenue laws of the United States, must advise the client promptly of the fact of such noncompliance, error, or omission. The practitioner must advise the client of the consequences as provided under the Code and regulations of such noncompliance, error, or omission.

## Nearby sections

- [31 C.F.R. § 10.20 (2026) § 10.20   Information to be furnished.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_20.md)
- [31 C.F.R. § 10.21 (2026) § 10.21   Knowledge of client's omission.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_21.md)
- [31 C.F.R. § 10.22 (2026) § 10.22   Diligence as to accuracy.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_22.md)
- [31 C.F.R. § 10.23 (2026) § 10.23   Prompt disposition of pending matters.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_23.md)
- [31 C.F.R. § 10.24 (2026) § 10.24   Assistance from or to disbarred or suspended persons and former Internal Revenue Service employees.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_24.md)
- [31 C.F.R. § 10.25 (2026) § 10.25   Practice by former government employees, their partners and their associates.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_25.md)
- [31 C.F.R. § 10.26 (2026) § 10.26   Notaries.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_26.md)
- [31 C.F.R. § 10.27 (2026) § 10.27   Fees.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_27.md)
- [31 C.F.R. § 10.28 (2026) § 10.28   Return of client's records.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_28.md)
- [31 C.F.R. § 10.29 (2026) § 10.29   Conflicting interests.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_29.md)
- [31 C.F.R. § 10.30 (2026) § 10.30   Solicitation.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_30.md)
- [31 C.F.R. § 10.31 (2026) § 10.31   Negotiation of taxpayer checks.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_31.md)
- [31 C.F.R. § 10.32 (2026) § 10.32   Practice of law.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_32.md)
- [31 C.F.R. § 10.33 (2026) § 10.33   Best practices for tax advisors.](https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_33.md)

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Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/CFR_T31_P10_S10_21. Check the current official text before relying on it. Not legal advice.