You received a CBP Form 29, Notice of Action

What the 20 days is, and what it is not

The text of 19 CFR 152.2 is one sentence: liquidation shall be made promptly and shall not be withheld for a period of more than 20 days from the date of mailing of such notice unless in the judgment of the Center director there are compelling reasons that would warrant such action.

That sentence is an instruction to CBP about its own timing. It does not say the importer must respond within 20 days, and it does not say a response is due at all. What it tells you is how much room you realistically have before the entry liquidates and the conversation changes character.

Four details in that sentence decide how you should read your own notice, and every one of them gets flattened in the summaries you will find elsewhere.

The wording quoted above is the operative sentence of 19 CFR 152.2. Nothing in the regulation sets a response deadline for the importer.

Action Proposed and Action Taken are on the form, not in the rule

The Form 29 has checkboxes labeled Action Proposed and Action Taken, and the difference between them is the first thing to look at. Proposed means CBP is telling you what it intends to do and is giving you the chance to respond before it does. Taken means it has already been done to the entry.

One caution, because this gets misquoted constantly: that phrasing lives on the form. It does not appear in 19 CFR 152.2, and attributing it to the regulation is a small error that signals the writer did not read the rule. If your notice is marked Proposed, you have an opening. If it is marked Taken, your route is different, and that is the next section.

The 20 day response window that people associate with a Form 29 comes from CBP's own operating document rather than from the regulation. The ACE Entry Summary Business Process Document (Trade-External) v11.0, December 2023, section 1.12 says that if the action is proposed, the importer will have 20 days to respond through the ACE Portal or DIS if applicable, and that if the action is taken and the entry liquidated, the trade will have to protest CBP's decision. So both figures are real and they are doing different jobs: the regulation limits how long CBP holds your liquidation, and this document is where CBP states your window to answer. That same document also says a courtesy copy of each CBP Form 29 should go to the broker, which is a quiet argument for having one: two sets of eyes see the notice, and one of them reads these every week.

What to do with a Notice of Action

Work backwards from the entry, not from the notice. CBP is telling you it disagrees with something you declared, so the useful question is what the entry claimed and what evidence stands behind it. If your documentation supports the original declaration, say so with the documents attached, and say it while the entry is still open.

If CBP is right, the fastest way out is usually to accept the change and pay the difference, because an entry that liquidates correctly stops accruing arguments. The expensive path is the middle one: disagreeing without evidence, slowly.

• Find the date of mailing on the notice. Every timing question starts there.
• Check whether the box is Action Proposed or Action Taken.
• Pull the entry summary and compare what CBP is proposing against what you actually declared.
• Assemble the evidence that supports your original position: invoices, payment records, origin documents, product literature for a classification dispute.
• Decide deliberately whether to contest or accept, and do it before liquidation rather than after.

After liquidation the route changes

Once the entry liquidates, the informal conversation is over and the formal one begins. The route then is a protest under 19 USC 1514, filed within 180 days of liquidation. That is a real and generous window, but it is a different process with its own requirements, and it is slower than getting the entry right before it closes.

We cover protests, post-summary corrections and the rest of the refund routes on our tariff refunds service page, so this page will not repeat the whole map. The point here is only that liquidation is the line between the two worlds, and a Form 29 is your warning that the line is coming.

What your own notice decides

Whether you are looking at a routine rate correction or the opening move of a broader review depends on what the notice says, which entry it names, and whether the same issue is live on other entries you have open. A classification change on one style usually means the same change is coming on every entry that carried it.

That is the analysis worth doing, and it needs your notice, your entry summary and your invoice. Ten minutes with those three documents answers more than an hour of reading about the regulation.