Not True: Reversing PIN at an ATM to Call the Police

A popular and long-running rumor states that if you enter your PIN at an ATM in reverse, it will serve as a panic code to summon the police.

It’s not true, but the technology does exist.

A popular helpful hint has circulated online which state that reversing one’s PIN at at ATM will act as a panic code to silently summon police. There have been attempts in the past to implement such a system, and the technology does exist, but as of 2015 it is not being used.

Potential Problems

Opponents have claimed that such a system could backfire in the face of a stressful holdup, with victims struggling to remember their PIN in reverse. It was also pointed out that certain palindrome combinations are the same in reverse (2112, 3333, etc) and would also prevent some PINs from summoning the police.

History

The idea of reversing a PIN to summon the police has been championed since the early 1990’s by Illinois lawyer Joseph Zingher, who patented an application called SafetyPIN. As far back as 1986 an emergency PIN system was first publicly suggested by Representative Mario Biaggi, who is also a former police officer. Despite discussion and some local laws pertaining to such emergency PINs, its implementation has not seen the light of day.

There have been several incarnations of the PIN reversal rumor, such as this one dating from 2008:

If you should ever be forced by a robber to withdraw money from an ATM, you can notify the police by entering your PIN in reverse. For example if your PIN is 1234 then you would put in 4321. The ATM recognizes that your PIN is backwards from the ATM card you placed in the machine. The machine will still give you the money you requested, but unknown to the robber, the police will be immediately dispatched to help you. This information was recently broadcasted on TV and it states that it is seldom used because people don’t know it exists. Please pass this along to everyone possible. Australian Federal Police. AFP Web site: (Link Removed)

The graphic below has circulated with the ATM Reversal story for several years.

Federal Trade Commission

A May 2010 report by the FTC (PDF) addressed the PIN reversal idea in a section entitled, “Study Required Under the Credit Card Act of 2009.” The study cited in the FTC report specified the PIN reversal idea to be evaluated:

The Act specifies two such technologies to be evaluated:
• “an emergency personal identification number that would summon a local
law enforcement officer to an [ATM] when entered into such [ATM] . . .”3
• “a mechanism on the exterior of an [ATM] that, when pressed, would
summon a local law enforcement [officer] to such [ATM].”4

The first security measure is commonly referred to as “reverse-PIN” or “emergency-PIN” technology and the second as “alarm button” technology.
Under the Act, the study should include: “an analysis of any technology
[allowing a distressed ATM user to electronically contact a law enforcement agency] that is currently available or under development”; “an estimate of the number and severity of any crimes that could be prevented by the availability of such technology”; “the estimated costs of implementing such technology”; and “a comparison of the costs and benefits of not fewer than 3 types of such technology.” The Commission is to issue a report of the findings of the study no more than nine months after the date of the enactment of the Act. The report is also to include “such recommendations for legislative
action as the Commission determines appropriate.”

FTC staff found that a few security systems allowing a distressed ATM customer to contact a local law enforcement agency electronically have been developed. However, no federal or state laws or regulations currently require the adoption of such measures, and FTC staff found no evidence that any of these proposed technologies have been deployed to any significant extent. Staff obtained a variety of anecdotal data, but was unable to find data sufficient to conduct a rigorous study of the issues set forth in the Act. This report describes the staff’s efforts to collect the data, discusses the anecdotal data received, and concludes, based on that anecdotal data, that the benefits of these ATM security technologies might not exceed the associated costs. At the same time, this anecdotal evidence does not allow for any definitive conclusions regarding the efficacy of emergency-PIN or alarm button systems to affect ATM crimes.

Bank of America Response

A footnote in the FTC report notes that Bank of America pointed out that “another problem with reverse PIN to consider is that it assumes the customer is approached prior to entering their PIN as opposed to after they have started their transaction. There has been no study to determine whether the ATM robberies are committed before or after the customer enters their PIN.”

Addressing the Problems

As noted above, many critics have pointed out that palindromic PINs such as 2222 or 4334 cannot be reversed. The SafetyPIN system, however, offered a solution to this by including a “plus one” algorithm for those containing 4 of the same numbers. This would mean that a customer with a PIN of 2222 would enter 3333 in a panic situation. An “inside out” algorithm could be used for other types of palindrome numbers, making 4334 into 3443, for example.

Critics have reiterated that it may be difficult to recall this information in the heat of a holdup.

Competing Technology

SafetyPIN’s reversing technology is not the only suggested solution to a panic mode at ATM’s. A system known as “ATMOnGuard” would require a single number to be entered in addition to the customer’s PIN. A PIN of 1234, for example, may add a digit such as “0” (making the panic PIN “12340”) to summon help.

The FTC notes that “the ATMOnGuard system has never been deployed at any ATMs in the U.S.”

Likely Impact on Crime

The FTC concluded that panic-mode PIN technologies “would not have a large impact on crime.” The reasons cited were a low incidence of ATM crimes, likelihood that a distressed victim would have the ability to activate a rarely-used emergency PIN, and that police response time would likely not be fast enough to deter such crimes. The implementation of this technology may simply prompt a a criminal to approach a potential victim after they have entered their PIN.

Final Word: Diebold’s Response

Diebold, a large manufacturer of ATMs, took the unusual measure of addressing the reverse PIN hoax on their website. Their statement should be the final (for now) word on this hoax:

Diebold is aware that the technology does exist which would allow ATM users to contact police in an emergency by punching in their PIN (personal identification number) in reverse, but to Diebold’s knowledge this technology has not yet been implemented anywhere in the United States.

The FTC also cited this response in their report.

Bottom Line

The long-running rumor that reversing your PIN at an ATM will summon police is incorrect. It has been suggested, along with other panic-mode technologies, but it has never been implemented. The problem of palindromic numbers such as 2222 and 4334 have been addressed, but it isn’t clear if a distressed victim would think clearly enough to enter a rarely-used panic PIN when under duress.

Updated December 8, 2015
Originally published November 2012