Customs and Border Protection’s own detention policy sets a ceiling of 72 hours in a CBP facility, but the honest answer to how long customs can detain you at the airport is that almost no traveler sees anything close to that. A referral to secondary inspection usually runs from a few minutes to a few hours. If CBP formally arrests you rather than just holding you for inspection, a separate constitutional clock kicks in: a judge must review probable cause within 48 hours.
Why CBP Can Hold You Without Suspicion
Ports of entry, including the international arrivals area of any airport, sit under what courts call the border search exception to the Fourth Amendment. Officers can question you, open your bags, and send you to secondary screening without a warrant, probable cause, or even reasonable suspicion.1Constitution Annotated. Amdt4.6.6.3 Searches Beyond the Border That is the starting point for every timeline that follows: the initial hold does not need a reason, so the limits on how long it can last come from CBP policy and, if things escalate, from the Constitution’s rules on arrest.
The exception is not unlimited. More invasive searches carry higher standards, and roving patrols away from the border need specific facts before stopping a vehicle. But at the customs hall itself, the officer’s authority to pull you aside is broad.
The 72-Hour Policy Ceiling
CBP’s internal rules, the TEDS standards (Transport, Escort, Detention, and Search), say that people should generally not be held in CBP facilities longer than 72 hours. Officers are directed to process, transfer, release, or repatriate detainees in the least amount of time operationally feasible.2U.S. Customs and Border Protection. National Standards on Transport, Escort, Detention, and Search
Two things about that number are worth understanding. First, it is a policy target rather than a statutory hard cap, and CBP has exceeded it during periods of high volume. Second, it applies to detention in a CBP facility, not to the short holds most airport travelers experience. Most people sent to secondary inspection are released or admitted after a wait that is uncomfortable but measured in hours, not days. Referrals happen for a range of reasons: a database hit, unusual travel patterns, incomplete paperwork, questions about the purpose of the trip, or random selection.
A secondary inspection that stretches into many hours without explanation, without food or water, or without any progress starts to raise legal concerns even before the 72-hour figure comes into play.
The 48-Hour Rule If You Are Arrested
Detention for inspection is not the same as arrest. If CBP moves from holding you for questioning to arresting you without a warrant, the Supreme Court’s decision in County of Riverside v. McLaughlin requires a judicial determination of probable cause within 48 hours. Once that deadline passes, the government carries the burden of justifying the delay, and administrative convenience is not enough.3Legal Information Institute. County of Riverside v. McLaughlin, 500 U.S. 44 (1991)
The line between an inspection hold and an arrest is not always obvious in the moment. Handcuffs, transfer to a separate facility, or being told you are being charged are all signals that the situation has shifted, and with it the applicable rules.
Your Rights While CBP Holds You
What you can and cannot refuse during a customs hold depends heavily on your immigration status. This is the point where many travelers get bad advice.
U.S. Citizens and Green Card Holders
If you are a U.S. citizen or lawful permanent resident, you must answer questions establishing identity and status. You can decline further questions about your travel, work, or associates. Declining will likely mean more time in secondary, but CBP cannot deny entry to a citizen or green card holder for refusing to answer questions beyond those needed to confirm who you are and your right to be in the country.
Citizens sent to secondary screening can ask that a lawyer be present during questioning. You can also refuse to hand over passwords to phones or laptops without losing your right to enter, though CBP may keep the device itself while you continue on.
Foreign Nationals Who Are Not Green Card Holders
Non-citizens who are not lawful permanent residents face a much narrower set of options. Refusing to answer questions or refusing to provide device passwords can be grounds for denying entry entirely. During secondary screening, foreign nationals generally are not permitted to contact an attorney or anyone else for assistance.
Treatment That Applies to Everyone
Anyone in CBP custody is entitled to humane treatment under the TEDS standards. Meals must come at regular intervals with snacks in between, food and water cannot be withheld as punishment, and clean drinking water must be available at all times. Emergency medical services must be called and the call documented when someone in custody has a medical emergency.2U.S. Customs and Border Protection. National Standards on Transport, Escort, Detention, and Search
Health intake interviews are required for people brought into custody, with extra attention to juveniles, pregnant individuals, and anyone with a visible medical concern. Juveniles must have that health interview repeated every five days and be held in safe and sanitary conditions with adequate food, water, emergency medical care, and temperature control.4U.S. Customs and Border Protection. CBP Medical Process Guidance
Phones, Laptops, and Passwords
Electronic devices sit at the center of many airport secondary inspections, and CBP splits device searches into two kinds under its January 2026 directive.5U.S. Customs and Border Protection. CBP Directive No. 3340-049B – Border Search of Electronic Devices
A basic search is an officer manually scrolling through what is on the device: photos, messages, files visible on the screen. It requires no suspicion at all. An advanced search means connecting external equipment to copy or analyze the device’s contents. Advanced searches require reasonable suspicion of a customs or law enforcement violation, or a documented national security concern, plus supervisory approval. National security cases need sign-off from a director-level official before the search starts.6U.S. Customs and Border Protection. CBP Directive 3340-049B
One detail catches people out. Using external equipment only to bypass a password, defeat encryption, charge a dead device, or view files on a drive without a screen does not count as an advanced search under the directive. CBP can crack a locked phone and then browse it manually as a basic search, without needing reasonable suspicion, so long as no forensic copying or analysis is done.
If you are a citizen or green card holder and you refuse to unlock the device, CBP may still detain the device even though it cannot deny you entry. Getting a phone back after it has been kept for forensic review can take weeks.
If CBP Keeps Your Property Instead of You
Detention holds you or your things temporarily. Seizure is different: CBP is taking property with the intent to forfeit it to the government. That triggers a separate process with its own deadlines, including a notice of seizure and either an administrative forfeiture (for property valued at $500,000 or less) or a judicial forfeiture in federal court.7Office of the Law Revision Counsel. 19 USC 1607 – Seizure; Value $500,000 or Less Missing the response window on a seizure notice is one of the most expensive mistakes in customs law: once administrative forfeiture becomes final, recovering the property is extremely difficult even if you had a valid defense.
If your bag, cash, phone, or merchandise did not come back with you, you are in the seizure track, not the detention track, and the paperwork you receive should tell you the case number and the deadline to respond.
Challenging What Happened
You have two main routes to push back after a CBP action at the airport. You can file a petition for remission or mitigation, which asks CBP to return your property or reduce a penalty. That petition can be submitted on CBP Form 4609 or as a signed letter in English, and it must include the seizure case number, the date and location, a description of the property, the facts you believe justify return, and proof of your ownership.8U.S. Customs and Border Protection. CBP Form 4609 – Petition for Remission or Mitigation of Forfeitures and Penalties These petitions are decided under 19 CFR Part 171.9eCFR. 19 CFR 171.1 – Petition for Relief
You can also file a formal claim contesting the forfeiture outright. A timely claim forces the government to go to court and prove that the property is subject to forfeiture, rather than asking CBP to exercise leniency. The trade-off is litigation cost and time.
For a hold you believe was unlawful or for mistreatment during detention, complaints go to the DHS Office of Inspector General and the DHS Office for Civil Rights and Civil Liberties. If you were arrested and held past the 48-hour probable cause deadline, that is a separate constitutional issue to raise with counsel as soon as you have access to one.