You got a CBP Form 28 (or 29). Here's the clock, the fork, and the plan.

The short answer: a CBP Form 28 is a request for information with a 30-day response expectation; a CBP Form 29 is a notice of action that gives you 20 days when the action is proposed. Answer the 28 completely and on time, figure out early whether you’re proving the entry right or discovering it wrong, and don’t let anyone treat the 29 like it has a 30-day window. It doesn’t.

What a CF-28 actually is

The CF-28 (“Request for Information”) is CBP asking you to back up something on an entry: a value, a classification, an origin claim, a preference claim. The form itself says the reply obligation is mandatory, invoking 19 U.S.C. 1509(a), and CBP’s stated practice (in its own submission to OMB) is: “The timeframe to respond is 30 days from the date of issuance of notice. If requested, an extension can be authorized under the discretion of CBP.” Note what that is and isn’t: the 30 days lives in the form’s instructions and CBP practice, not in a regulation, and an extension is a favor you request from the officer named on the form, not a right.

It arrives through the ACE portal, mail, or email; the answer goes back through ACE or the Document Image System. And the certification block must be signed by a corporate or company official of the importer, not the broker, which tells you who ultimately owns the answer.

By CBP’s own published estimate, the agency expects roughly 13,400 CF-28 responses a year (a paperwork-burden estimate, not a count, and one CBP revised down from 62,000). These are routine. What you do in the 30 days is what decides whether yours stays routine.

Days 1-5: read it the way CBP will read your answer

Confirm receipt, diary the deadline, and pull the complete entry package: the 7501, the commercial invoice, packing list, proof of payment, any ruling, the classification rationale. Then read what’s actually being asked. A value question (related parties, assists, royalties) is a different project from an origin question or a preference-claim question, and the documents that answer each are different.

Also diary a second date: the entry’s scheduled liquidation. A CF-28 often comes with CBP extending liquidation (it may, one year at a time, up to three extra years, exactly because information it needs “is not available”), and your protest rights later run from the liquidation that eventually happens.

Days 5-20: find out which fork you’re on

Everything downstream depends on one honest question: was the entry right?

Fork one: the entry was right, and you’re proving it. Then the response is an evidence project. Answer every question asked, completely, with documents, and nothing more than what’s asked. Reasonable care is the standard you’re being measured against, and CBP’s own penalty guidelines call out things like ignoring a binding ruling or an obviously wrong classification. Keep a full copy of what you sent and proof of transmission. In one published Court of International Trade case (TR International), CBP recorded no response to a CF-28 the importer said it had sent, then proposed converting the entries to antidumping-duty entries at 156.87% plus 8.14% countervailing, on 20 days’ notice. Whatever the truth of that record, “we can prove exactly what we sent and when” is the position you want.

Fork two: the CF-28 just told you the entry was wrong. Stop and size it before answering. Is it this entry, or a pattern across entries? A correction on one entry has tools; a pattern has different tools, and the order matters:

• Post Summary Correction, when it’s available: generally within 300 days of entry or up to 15 days before scheduled liquidation, whichever is earlier. Two traps: a PSC can’t be filed while the entry is under CBP review, which is often precisely what the CF-28 initiated, and can’t be filed on protested entries. (Since August 5, 2026, PSC duty increases must be paid by ACH, with AD/CVD increases due within three business days.)
• Prior disclosure, when exposure spans entries or culpability could be questioned: made properly before (or without knowledge of) a formal investigation, it caps a negligence or gross-negligence penalty at interest on the actual duty loss, and there’s no penalty at all where the loss is still only potential because the entry hasn’t liquidated. It has content requirements, requires tendering the duties, and the burden of showing you didn’t know about an investigation sits with you. This is the point where a customs attorney belongs in the room, both for judgment and for privilege.

What you must not do is nothing. An unanswered CF-28 can draw a bond demand to redeliver the merchandise, and it reliably draws the next form.

The CF-29, decoded

The CF-29 (“Notice of Action”) is CBP telling you about an action that will increase duties. Three things to read immediately:

1. The checkbox: proposed or taken. “Is proposed” means you have 20 days from the notice to furnish written reasons against it; after 20 days, the entry is liquidated or changed as proposed. “Has been taken” means the argument has moved downstream: the entry will liquidate (or has), and your remedy is a protest within 180 days of liquidation.
2. The action type: rate advance, value advance, excess quantity or weight, or other.
3. The line on its face: “This is NOT A Notice of Liquidation.” It’s also not a bill. It’s the formal warning shot, backed by 19 CFR 152.2, which requires the notice when a duty increase on an entry exceeds $15 and limits how long liquidation waits after it.

The 20-day window is short on purpose. If a proposed CF-29 arrives and the underlying issue is real (an AD/CVD scope question, say), the response may need to run on two tracks at once: the written disagreement to CBP, and the separate remedy in the right forum. In TR International, the court dismissed the importer’s lawsuit precisely because a protest and a Commerce scope ruling were the remedies that existed for its situation.

If it becomes a penalty case

The penalty statute (19 U.S.C. 1592) has three culpability tiers with statutory ceilings (up to twice the duty loss for negligence, four times for gross negligence, and the domestic value of the merchandise for fraud), but what CBP actually assesses usually follows its published mitigation ranges, which start at half the duty loss for negligence. Three structural facts shape strategy more than the multipliers: the burden is on the importer to prove an error wasn’t negligent once CBP establishes it happened; CBP can recover the lost duties themselves regardless of any penalty and despite final liquidation; and the five-year statute of limitations runs from the violation for negligence, but from discovery for fraud, which is part of why fraud allegations change everything. A prepenalty notice comes with 30 days to respond (as few as 7 if the limitations clock is short); a penalty notice gives 60 days to petition for relief.

Where our lane ends

A broker’s job here is real: build the evidence file, get the classification and valuation analysis right, transmit the response properly, file the PSC or the protest as your authorized agent, and, when we spot noncompliance, tell you promptly and advise the fix (the regulations require exactly that of us). The honest line: once the question is culpability rather than classification, once a prior disclosure is being drafted, or once a prepenalty notice exists, you want a customs attorney leading, with your broker supporting. Anyone who tells you otherwise is selling.

General information as of August 30, 2026, not legal advice for a specific entry. Got one of these forms and want a second set of eyes on the entry behind it? That’s a quick, no-obligation look. More on how we handle compliance day-to-day is in Services and understanding reasonable care.

Sources

• CBP Form 28 (rev. 07/16) and CBP Form 29 (rev. 06/14) instructions; CBP Supporting Statement to OMB, control no. 1651-0023
• 19 CFR 151.11, 19 CFR 152.2, 19 CFR 159.12, 19 CFR 162.74, 19 CFR Part 171 App. B
• 19 U.S.C. 1592, 19 U.S.C. 1514, 19 U.S.C. 1621
• 91 FR 41053 (PSC test modifications, operational Aug. 5, 2026)
• TR Int’l Trading Co. v. United States, CIT Slip Op. 20-34 (Mar. 16, 2020)