NoteHomeland Security Department, U.S. Customs and Border Protection · OtherEffective Oct 1, in 6 days3/3 quoted sentences found in the source

CBP will pay 7 percent interest on customs duty refunds to non-corporate importers in the fourth quarter, 6 percent to corporations

CBP's quarterly notice sets the interest rates on overdue customs accounts and on refunds of customs duties for October 1 through December 31, 2026, unchanged from the previous quarter: 7 percent on underpayments for everyone, 7 percent on refunds to non-corporations, and 6 percent on refunds to corporations. IEEPA refunds paid through CAPE include interest, so the rate is part of what a refund is worth.

Refunds, non-corporate7 percent
Refunds, corporate6 percent
Applies fromOctober 1, 2026

What the document says

Matched to source. Refund and underpayment rates are unchanged for the quarter that starts October 1.
Matched to source. The rates apply from October 1.
Matched to source. The rates come from the IRS formula: the federal short-term rate plus three points, or plus two for corporate refunds.

Who does this affect?: Any importer waiting on a duty refund (IEEPA refunds through CAPE, Section 301 exclusion refunds, protests) and any importer with an overdue customs bill; sole proprietors and partnerships earn the higher refund rate.
What it costs: Refunds of customs duties earn 7 percent interest for non-corporations and 6 percent for corporations in the quarter beginning October 1, 2026; overdue accounts are charged 7 percent.
What to check: When a refund arrives, check that the interest line matches the quarter's rate for your entity type; if you import as a sole proprietor or partnership rather than a corporation, the refund rate is a point higher.

The headline, summary, who, cost, and what-to-check lines are our reading of the document, not the document’s words and not advice.

Primary source

Quarterly IRS Interest Rates Used in Calculating Interest on Overdue Accounts and Refunds of Customs Duties