Title 26 — Internal Revenue CodeRelease 119-73

§6663 Imposition of fraud penalty

Title 26 › Subtitle Subtitle F— - Procedure and Administration › Chapter CHAPTER 68— - ADDITIONS TO THE TAX, ADDITIONAL AMOUNTS, AND ASSESSABLE PENALTIES › Subchapter Subchapter A— - Additions to the Tax and Additional Amounts › Part PART II— - ACCURACY-RELATED AND FRAUD PENALTIES › § 6663

Last updated Apr 6, 2026|Official source

Summary

If part of a tax underpayment is due to fraud, add a penalty equal to 75% of the fraud. If the IRS proves any fraud, it treats the whole underpayment as fraudulent unless the taxpayer shows, more likely than not, some part was not. On joint returns, a spouse is liable only for fraud they committed.

Full Legal Text

Title 26, §6663

Internal Revenue Code — Source: USLM XML via OLRC

(a)If any part of any underpayment of tax required to be shown on a return is due to fraud, there shall be added to the tax an amount equal to 75 percent of the portion of the underpayment which is attributable to fraud.

(b)If the Secretary establishes that any portion of an underpayment is attributable to fraud, the entire underpayment shall be treated as attributable to fraud, except with respect to any portion of the underpayment which the taxpayer establishes (by a preponderance of the evidence) is not attributable to fraud.

(c)In the case of a joint return, this section shall not apply with respect to a spouse unless some part of the underpayment is due to the fraud of such spouse.

Legislative History

Notes & Related Subsidiaries

Statutory Notes and Related Subsidiaries

Effective Date

Section applicable to returns the due date for which (determined without regard to extensions) is after Dec. 31, 1989, see section 7721(d) of Pub. L. 101–239, set out as an

Effective Date

of 1989 Amendment note under section 461 of this title.

Reference

Citations & Metadata

Citation

26 U.S.C. § 6663

Title 26 — Internal Revenue Code

Last Updated

Apr 6, 2026

Release point: 119-73