WASHINGTON, July 25, 2026 — A 2010 Federal Trade Commission report studied the viability of duress codes for ATMs and concluded that deployment costs outweigh the likelihood of deterring criminal activity. The agency noted that duress PINs have never been actually implemented in any ATM. A duress code is a covert distress signal used by someone coerced by hostile persons to warn others that they are acting against their will.
The warning can be embedded in normal communication—a code-word or phrase—or incorporated into authentication as a panic password or duress PIN distinct from normal credentials. These mechanisms are related to panic alarms and often achieve the same outcome.
In civilian use, some home and property alarm systems use duress PINs where the last two digits of the reset code are switched around. Entering that code under duress can trigger a silent alarm alerting police or security. The implementation has been controversial because of false alarm claims.
A similar mechanism, SafetyPIN, was proposed for ATMs. The figure that matters: transponder code 7500.
Civilian and commercial aircraft use that as a duress code to indicate hijacking. Airlines also maintain a verbal hijack code. For cell phone communication, a covert phrase—such as asking about a nonexistent person or object, e.g., “What is Cindy barking at?” when the dog has a different name or there is no dog—can signal duress.
A widely shared urban legend involves calling emergency services and pretending to order pizza delivery, which did occur in Brazil.
By the numbers: vulnerabilities
Technical vulnerabilities exist. An adversary who knows a duress PIN exists can request the PIN in advance and ensure the modified PIN is entered. If the adversary does not know which PIN is correct, they may randomly choose between two possible codes, succeeding half the time.
In access control, a single panic password is insufficient because an adversary who knows the system can force authentication twice with different passwords, gaining access on at least one attempt. More complex panic password schemes have been proposed.
On the financial side, duress activity includes withdrawing cash from an ATM using a specific credit card instead of a debit card. That triggers email alerts from credit card companies. But technical issues include notification delay, cellular network availability, and lack of location disclosure.
The bottom line: duress PINs have been implemented in mobile operating systems such as GrapheneOS. There, entering the duress PIN causes the phone to perform a specific action.
Investors will note that the concept spans home alarms, ATMs, cell phones, aircraft, and mobile OS. The FTC report remains the most thorough federal analysis, and no ATM deployment has followed. What to watch next: whether any major ATM network, mobile OS, or alarm system adopts duress codes in a way that addresses the documented vulnerabilities and false-alarm concerns.
