Customs duty interest rates for Oct 1, 2026: what brokers and claimants should use
CBP published the quarterly IRS interest rates for customs underpayments and refunds. Update calculators for duty bills and drawback/refund interest as of October 1, 2026.
CBP has published the quarterly IRS interest rates used to calculate interest on overdue accounts (underpayments) and refunds (overpayments) of customs duties. The notice is 91 FR 60141 (FR Doc. 2026-19292). Rates are applicable as of October 1, 2026.
Authority is 19 U.S.C. § 1505 (and Treasury Decision 85-93), which ties customs interest to the Internal Revenue Code rates under 26 U.S.C. §§ 6621 and 6622. Section 6621 sets different overpayment rates for corporations and non-corporations.
Quarter beginning Oct 1, 2026: underpayments 7% (corp and non-corp); overpayments 7% non-corp / 6% corp.
Rates for October 1 through December 31, 2026
Underpayments (corp and non-corp): 7% (Federal short-term 4% + 3)
Overpayments (non-corporations): 7% (4% + 3)
Corporate overpayments: 6% (4% + 2)
Table period Jul 1, 2026-Dec 31, 2026 shows the same 7 / 7 / 6 rates
In Revenue Ruling 2026-15, IRS set the Federal short-term rate at 4% for the calendar quarter beginning October 1, 2026. The summary table in the CBP notice groups July 1, 2026 through December 31, 2026 as one block at 7% underpayments, 7% overpayments, and 6% corporate overpayments, so the Oct 1 quarter continues the rates already shown for the immediately prior July-start period in that table. Rates are subject to change again for the quarter beginning January 1, 2027.
Where brokers and claimants actually use these
- Duty underpayments: interest on additional duties, taxes, and fees billed after entry or at liquidation/reliquidation.
- Refunds / overpayments: interest on refunds of customs duties, including drawback overpayments when interest applies under the refund rules.
- Entity type matters on overpayments: corporate claimants use 6%; non-corporate use 7% for the Oct-Dec 2026 quarter.
Update brokerage interest calculators, drawback claim interest worksheets, and protest/refund trackers to 7/7/6 as of October 1, 2026. Confirm whether the party of interest is a corporation before applying the overpayment rate.
- CBP quarterly interest notice: 91 FR 60141 (FR Doc. 2026-19292); applicable October 1, 2026.
- Underpayments: 7% for corporations and non-corporations. Overpayments: 7% non-corp / 6% corp.
- Table shows Jul 1-Dec 31, 2026 at the same 7 / 7 / 6 rates; authority 19 U.S.C. § 1505 and 26 U.S.C. § 6621.
- Use these rates for duty underpayment interest and for refund interest, including applicable drawback overpayments.
- Next reset window: quarter beginning January 1, 2027.
- Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds of Customs Duties (91 FR 60141; FR Doc. 2026-19292) · U.S. Customs and Border Protection, Department of Homeland Security
This article is for general information and is not legal or tax advice. Drawback eligibility depends on your specific facts, and final refunds are determined by CBP at liquidation. Consult a licensed customs broker or attorney for your situation.