A border phone search can happen without a warrant at any U.S. port of entry. In the Ninth Circuit, which covers California, a manual search of a phone needs no suspicion, while a forensic search needs reasonable suspicion of digital contraband. The Second Circuit held in September 2026 that no suspicion is required for a manual phone search.
Key Takeaways
- The border-search exception allows routine searches of travelers and their belongings without a warrant or suspicion.
- In the Ninth Circuit, Cotterman (2013) and Cano (2019) require reasonable suspicion for a forensic phone search and limit it to looking for digital contraband.
- The First Circuit in Alasaad (2021) held that neither manual nor forensic searches require a warrant, and that basic searches require no suspicion.
- The Second Circuit in United States v. Alisigwe (Sept. 17, 2026) upheld a manual phone search without a warrant or suspicion.
- A petition asking the Supreme Court to resolve the issue, Anibowei v. Blanche, No. 26-208, is pending. The Court has requested a response.
What Is the Border-Search Exception?
The government has long had broad authority to search people and property entering the country, to enforce customs and immigration laws and stop contraband. Searches at the border are considered reasonable simply because they occur there. Courts have recognized limits only for highly intrusive searches, such as body-cavity searches, which require reasonable suspicion. The question for the last decade has been whether a modern smartphone, with its vast store of private information, falls into the routine category or the intrusive one.
What Is the Rule for a Border Phone Search in California?
California is in the Ninth Circuit, which has the most protective federal rule in the country. In United States v. Cotterman, the en banc court held that a forensic examination of a laptop, using software to analyze the hard drive, was intrusive enough to require reasonable suspicion. In United States v. Cano, which arose from an arrest at the San Ysidro port of entry, the court applied Cotterman to phones and went further. It held that a forensic phone search must be limited to looking for digital contraband itself, such as child sexual abuse material, rather than evidence of a crime like drug smuggling. Manual searches, where an officer scrolls through the phone, require no suspicion.
How Do Other Circuits Handle Border Phone Searches?
Other circuits are less protective. In Alasaad v. Mayorkas, a civil case brought by EFF and the ACLU on behalf of 11 travelers, the First Circuit held that basic searches need no suspicion and that advanced searches need no warrant. It expressly disagreed with Cano‘s contraband-only limit, stating that it could not agree with the Ninth Circuit’s “narrow view of the border search exception.”
On September 17, 2026, the Second Circuit decided United States v. Alisigwe. It held that a manual search of a traveler’s phone at the border requires neither a warrant nor reasonable suspicion. The court left open whether a forensic search requires reasonable suspicion. A Cleary Gottlieb client memo notes that the decision deepens the circuit split. Earlier versions of this post described a 2025 Second Circuit ruling that required a warrant for border phone searches; no such ruling exists, and Alisigwe went the other way.
Will the Supreme Court Take Up Border Phone Searches?
Possibly. In Anibowei v. Blanche, No. 26-208, petitioner George Anibowei, whose phone was searched when he reentered the country, asks the Court to decide whether the Fourth Amendment allows warrantless border searches of cell phones. The petition was filed in August 2026 from the Fifth Circuit. The federal respondents initially waived a response, but after a long list of amicus briefs, the Court requested one on September 29, 2026. It is now due November 30, 2026. The Supreme Court’s 2026 decision in Chatrie v. United States, which treated cell-phone location history as protected even when held by a third party, may give the petitioner additional support.
What Should Travelers Know?
- Citizens cannot be denied entry for refusing to unlock a phone, but the device may be detained for further inspection.
- Noncitizens face greater risk, including possible denial of entry.
- Cloud data is generally outside CBP’s stated border-search policy, which covers data stored on the device. Placing a phone in airplane mode before inspection limits what is accessible.
- Attorney-client material should be identified to the officer, which triggers special handling procedures.
- Criminal cases in the Southern District of California should test whether any forensic search was supported by reasonable suspicion of digital contraband under Cano.
Related reading from Darren Chaker includes border searches of laptops, phone and computer search warrants, compelled decryption, and digital rights advocacy.
Key Authorities
- United States v. Cotterman, 709 F.3d 952 (9th Cir. 2013) (en banc), slip op. at 28 (“We therefore hold that the forensic examination of Cotterman’s computer required a showing of reasonable suspicion, a modest requirement in light of the Fourth Amendment.”).
- United States v. Cano, 934 F.3d 1002 (9th Cir. 2019), slip op. at 22 (“Accordingly, we hold that manual searches of cell phones at the border are reasonable without individualized suspicion, whereas the forensic examination of a cell phone requires a showing of reasonable suspicion.”).
- Alasaad v. Mayorkas, 988 F.3d 8 (1st Cir. 2021), slip op. at 17 (“We too hold that neither a warrant nor probable cause is required for a border search of electronic devices.”).
- United States v. Alisigwe, No. 24-960, slip op. at 5 (2d Cir. Sept. 17, 2026) (holding that manual border searches of cell phones require neither a warrant nor reasonable suspicion).
How Is AI Used in Border Phone Searches?
The border is where AI forensics meets the weakest Fourth Amendment protection. Officers can look through a traveler’s phone without a warrant, and federal agencies are testing AI to read that data faster. Darren Chaker, an EnCase Certified Examiner (EnCE) with an Open-Source Intelligence (OSINT) certification, counterintelligence studies at American Public University, and ongoing training in AI forensics (see his Google Developer profile), explains what the government’s own records show.
What is the difference between a basic and an advanced border search?
CBP replaced its 2018 policy with Directive 3340-049B, effective January 1, 2026. A basic search can happen “with or without suspicion.” An advanced search, where an officer connects equipment, wired or wireless, to copy or analyze a device, requires reasonable suspicion or a national security concern plus supervisor approval at the GS-14 level or higher. The new directive also says that using equipment merely to make content available, including to “translate content,” is not an advanced search. That line matters for AI: machine translation may fall on the basic side, while AI analysis of a copied phone is advanced.
What AI tools has DHS disclosed for phone data?
DHS publishes an AI use-case inventory. It lists a CBP tool called “Smartphone Information Forensics Triage,” marked as pre-deployment and high-impact, which “Translates messages to English where applicable. Summarizes the content of text messages and presents that summary to the system operator” (DHS AI Use Case Inventory). The same inventory lists the Traveler Verification Service, which uses facial comparison to confirm travelers’ identities at ports of entry.
Why does AI summarization matter at the border?
Machine translation can drop slang or tone, and a short summary can make innocent messages look suspicious. If an officer relies on a summary to detain a traveler or seize a device, the defense should demand the native messages, the translation, and the summary side by side.
Can AI-derived border evidence be challenged in court?
Yes. Appellate courts require that complex software be explained by qualified witnesses, and New Jersey ordered source code produced under a protective order. Proposed Federal Rule of Evidence 707 would also apply the Rule 702 reliability test to machine-generated evidence; as of May 2026, the rule was still under study (Reuters).
How can travelers protect their phones at the border?
- Travel with less data. Log out of cloud accounts and turn on airplane mode before inspection; CBP’s directive limits searches to data stored on the device.
- Use a strong passcode instead of face or fingerprint unlock.
- Ask for a custody receipt (CBP Form 6051D) if a device is detained; the 2026 directive requires one.
- If AI tools were used, request the tool’s name, its output, and the human review record in any later case.
Facial comparison at ports of entry also links to the issues in biometric unlocking, and the broader civil liberties stakes are covered in AI surveillance and digital rights advocacy.
Frequently Asked Questions
Can border agents search my phone without a warrant?
Yes. Every federal appeals court to decide the issue has held that a warrant is not required for a border phone search. In the Ninth Circuit, a forensic search requires reasonable suspicion.
What is the difference between a manual and forensic phone search?
A manual search is an officer looking through the phone by hand. A forensic search uses external equipment or software to copy and analyze the data, and in the Ninth Circuit it requires reasonable suspicion.
Has the Supreme Court decided border phone searches?
Not yet. A petition in Anibowei v. Blanche, No. 26-208, asks the Court to take the issue, and the Court has requested a response due November 30, 2026.
This article is for general information only and is not legal advice. Learn more about Darren Chaker. Last reviewed November 2026.
