26 U.S.C. § 6676
Erroneous claim for refund or credit
If a claim for refund or credit with respect to income or employment tax is made for an excessive amount, unless it is shown that the claim for such excessive amount is due to reasonable cause, the person making such claim shall be liable for a penalty in an amount equal to 20 percent of the excessive amount.
For purposes of this section, the term “excessive amount” means in the case of any person the amount by which the amount of the claim for refund or credit for any taxable year exceeds the amount of such claim allowable under this title for such taxable year.
For purposes of this section, any excessive amount which is attributable to any transaction described in section 6662(b)(6) shall not be treated as due to reasonable cause.
This section shall not apply to any portion of the excessive amount of a claim for refund or credit which is subject to a penalty imposed under part II of subchapter A of chapter 68.
Section 1409(d) of Pub. L. 111–152, which directed the amendment of section 6676 without specifying the act to be amended, was executed to this section, which is section 6676 of the Internal Revenue Code of 1986, to reflect the probable intent of Congress. See 2010 Amendment note below.
A prior section 6676, added Pub. L. 87–397, § 1(b),
2025—Subsec. (a). Pub. L. 119–21 substituted “income or employment tax” for “income tax”.
2018—Subsec. (c). Pub. L. 115–141 substituted “reasonable cause” for “reasonable basis” in heading.
2015—Subsec. (a). Pub. L. 114–113, § 209(c)(1), substituted “is due to reasonable cause” for “has a reasonable basis”.
Pub. L. 114–113, § 209(b), struck out “(other than a claim for a refund or credit relating to the earned income credit under section 32)” after “income tax”.
Subsec. (c). Pub. L. 114–113, § 209(c)(2), substituted “due to reasonable cause” for “having a reasonable basis”.
2010—Subsecs. (c), (d). Pub. L. 111–152 added subsec. (c) and redesignated former subsec. (c) as (d). See Codification note above.
Amendment by Pub. L. 119–21 applicable to claims for credit or refund after
Pub. L. 114–113, div. Q, title II, § 209(d)(2),
Amendment by Pub. L. 111–152 applicable to refunds and credits attributable to transactions entered into after
Pub. L. 110–28, title VIII, § 8247(c),