Not every duty error is caught at the time of entry. When one slips through, importers are not stuck with it. A post-summary correction is the mechanism for fixing an entry after it has been filed, and it can recover overpaid duty.
What a post-summary correction is
A post-summary correction, or PSC, is a formal update to an entry summary submitted to CBP after the original filing. It lets an importer correct errors in classification, valuation, or duty before the entry liquidates. If the correction reduces the duty owed, it can recover the overpayment.
When to use one
PSCs are useful whenever you discover an error on a filed entry: a wrong HTS code, a missed exclusion, an incorrect value. The key constraint is timing. Corrections generally have to be made before the entry liquidates, which is another reason not to sit on a known issue.
Why they go unfiled
Plenty of correctable entries never get corrected simply because no one circles back to file the PSC. The error is noticed, or would be if anyone looked, but the follow-through does not happen. That unfiled correction is unrecovered money.
Getting corrections filed
Specialists handle post-summary corrections as part of a recovery review, identifying correctable entries and filing before deadlines pass. If you suspect errors on past entries, a free eligibility check is the fastest way to find out whether a correction can turn them into a refund.