Liquidation is when CBP finalizes your entry and the duty bill locks in. By law it has to happen within a year of entry, and in practice the typical entry liquidates in about 314 days. After that you have 180 days to protest on CBP Form 19 if the numbers are wrong.
Liquidation is the deadline, not the paperwork
Most importers think of liquidation as a form. It is not. It is the moment CBP stops reviewing your entry and the duty assessment becomes final. Until liquidation, the entry is open: CBP can ask questions, change the classification, or adjust the value. After liquidation, the bill stands unless you protest it or CBP reliquidates it.
The statute behind this is 19 USC 1504. It gives CBP one year from the date of entry to liquidate. If CBP does nothing inside that year, the entry liquidates by operation of law at the rate and value you claimed. That is called deemed liquidation, and it cuts both ways: it protects you from an endless review, but it also locks in whatever you filed, mistakes included.
The 314-day number, and why it is not a promise
CBP's own data puts the typical liquidation at about 314 days after entry. That is the average across entries that liquidate normally, not a deadline you can plan around. Entries with open questions, pending AD/CVD reviews, or classification disputes can sit much longer, and CBP can extend the one-year window when it has a reason.
The practical point is that you should not wait for liquidation to check your work. The entry summary, CBP Form 7501, is due within 10 working days after entry, and that is your first real chance to catch an error. Fix it with a post-summary correction while the entry is still open. Once liquidation hits, your only lever is the protest window, and that has its own clock.
Form 29: the 20-day letter that changes the bill
Before CBP liquidates at a rate different from what you claimed, it usually sends a Notice of Action, CBP Form 29. The form tells you what CBP wants to change and why: a different classification, a higher value, a missing marking. You have 20 days to respond, and the response is your chance to argue the point with evidence before the entry closes.
Twenty days is shorter than it sounds. The letter goes to the importer of record, and if it lands in a shared inbox nobody watches, the clock runs anyway. Importers who answer Form 29 with documents, a classification ruling, or a valuation memo often keep the original rate. Importers who miss the window find the higher rate baked into the liquidation, and then they are protesting instead of explaining.
The protest window: 180 days on Form 19
After liquidation, the protest is your remedy. CBP Form 19 must be filed within 180 days of the liquidation date, and it has to state the grounds clearly: the classification was wrong, the value was wrong, the duty was over-assessed. A protest that just says the bill feels high will not survive review.
One detail importers miss: the 180 days runs from liquidation, not from when you noticed the problem. If you only check the liquidation notice three months in, you have three months left, not six. Track liquidation dates the same way you track entry dates, and treat a protest as a filing with a hard deadline, because that is exactly what it is.
Keep reading
Related guides on this site: how post-summary corrections work before liquidation liquidation notices and when CBP extends the clock what reasonable care looks like before you file More from LandedWatch.
Frequently asked questions
When does an entry liquidate?
By law, within one year of the entry date under 19 USC 1504. In practice the typical entry liquidates in about 314 days. Entries with open questions or pending AD/CVD reviews can take longer, and CBP can extend the window.
What is deemed liquidation?
If CBP does not liquidate an entry within one year, the entry liquidates automatically at the rate and value you claimed. It protects you from endless review, but it also locks in any mistakes in your filing.
How long do I have to respond to a CBP Form 29?
Twenty days from the date of the notice. The response is your chance to argue the classification or value with evidence before CBP liquidates at the higher rate, so treat the deadline as firm.
Can I protest after liquidation?
Yes, on CBP Form 19 within 180 days of the liquidation date. The protest must state the grounds clearly, such as a wrong classification or over-assessed value. The clock runs from liquidation, not from when you noticed the problem.