Interest rates applicable to underpaid and overpaid customs duties have been set for the calendar quarter beginning July 1, 2026 — a routine but easy-to-miss update that affects any importer dealing with a duty correction, protest, or refund this quarter.
Why This Matters More Than It Sounds
These rates apply whenever duty is paid late (interest owed to CBP) or when a refund is due following a successful protest or reconciliation (interest owed to the importer). Getting caught unaware of a rate change can mean an unexpected interest charge on a routine correction.
What to Check
- Confirm the current quarter's underpayment and overpayment rates before finalizing any duty correction or protest calculation
- Note that corporate and non-corporate rates can differ slightly — make sure you're applying the correct one for your entity type
- Factor interest exposure into your timeline when a classification or valuation issue is under review, since delays compound the cost
A duty correction that takes an extra quarter to resolve isn't just a paperwork delay — it's an extra quarter of interest accruing one way or the other.