ATMs Have the Wrong Number

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I have long been aware that there were different telephone keypad layouts that put letters on different number buttons, but it was only this past week that I really started researching this topic in detail.

The most amazing thing I have discovered is that while the most common layout on phones is an international standard (ITU-T E.161), the other most common numeric keypad (aside from calculators), the PIN pad found on ATM machines and other banking devices, typically puts the letters Q and Z on the number 1 button.

Why this came to be is beyond me, since I have been able to find no specification that places Q and Z on the 1 button. And the current European ATM standards I have found quite clearly specify the ITU-T E.161 layout. This of course means that as more people do banking on their mobile phones in addition to ATMs, anyone that uses a Q or Z in their PIN will have difficulty switching between devices.

Aside from there being no published standard that places Q and Z on the 1 button, there is no good reason to put these letters anywhere but where E.161 specifies. The Predecessor of the ITU-T standards group researched this in 1991, with the result showing that people preferred Q and Z on the 7 and 9 keys by over 83%.


Author: Peter Sheerin

Peter Sheerin is best known for the decade he spent as the Technical Editor of CADENCE magazine, where he was the acknowledged expert in Computer-Aided Design hardware and software. He has a long-standing passion for improving usability of software, hardware, and everyday objects that is always interwoven in his articles. Peter is available for freelance technical writing and product reviews, and is exploring career opportunities in interaction design. His pet personal project is exploring the best ways to harmonize visual, tactile, and audible symbols for improving the effectiveness of alerting systems.

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