Hold Side + either Volume button until the Power off / Medical ID / SOS screen appears. Dismiss it — Face ID (or Touch ID) is now disabled. Your iPhone will require the passcode to unlock.

Why this matters

In the US, courts are split on whether police can compel you to unlock your phone with biometrics:

• Passcodes are generally protected by the Fifth Amendment as "contents of your mind" — similar to a safe combination. Courts have broadly held that forcing someone to reveal a passcode is testimonial and potentially self-incriminating.
• Biometrics are more legally vulnerable. Several courts have ruled that compelling a fingerprint or face scan is like providing a physical sample (DNA, handwriting) — not testimonial. The 9th Circuit ruled in US v. Payne (2024) that an officer physically placing a suspect's finger on a phone didn't violate the Fifth Amendment.
• But it's not settled. Other courts have found biometric unlocking is testimonial, arguing that "biometric features serve the same purpose as a passcode, pragmatically rendering them functionally equivalent" (In re Residence in Oakland, N.D. Cal. 2019).

Bottom line: Your passcode has stronger legal protection than your face. Hard-locking takes two seconds and shifts your phone from the weaker biometric standard to the stronger passcode standard.

When to use it

• Before any encounter with law enforcement
• At border crossings or international checkpoints
• If you're at a protest or demonstration
• Any time you feel your device security could be compromised

For more on the legal landscape, see the NACDL's Compelled Decryption Primer.