1967
The First Cash Dispenser
Barclays Bank in Enfield, London installs the world's first cash dispenser, designed by John Shepherd-Barron. It used paper cheques treated with carbon-14 rather than a numeric code — security through chemistry.
Customer Reference
Numbers and letters on
your cash machine keypad
Every cash machine worldwide uses the same keypad layout — a 3×4 grid of numbers paired with letter groups. What appears to be a random arrangement of cash machine keypad numbers and letters is in fact a decades-old international standard.
3M+
Machines worldwide
1963
Standard established
26
Letters across 8 keys
About the layout
Not arbitrary. An international standard.
The letters visible beneath each number follow ITU E.161, an international standard originally designed for telephone dialling. Each digit is assigned a fixed group of letters: 2 carries A, B and C; 3 carries D, E and F — continuing in sequence to 9, which holds W, X, Y and Z.
Keys 1, 0, * and # carry no letters. This is a convention carried over from early telephony, where those positions were reserved for operator and signalling functions rather than alphabetic input.
Helpful to know: Because the mapping is standardised, any four-letter word can serve as a memorable way to recall your numeric PIN on any cash machine worldwide.
Background
A brief history of the cash machine keypad
From the first cash dispenser in 1967 to the 3 million machines operating today.
1972
Numeric Codes Introduced
Lloyds Bank introduces the first PIN-based cash machine. The 4-digit format was chosen partly because inventor James Goodfellow's wife could only reliably recall four digits. The keypad layout mirrored the telephone standard.
1988
A Global Network
The PLUS network connects cash machines internationally, requiring the numeric keypad to become a truly universal standard — the same 3×4 grid appearing on machines from Tokyo to Toronto.
1999
Letter Assignments Matter Again
Predictive text input on mobile phones — using the same key-to-letter mapping found on cash machine keypads — becomes widespread on Nokia handsets. The letter assignments, long overlooked, suddenly carry everyday relevance.
2007
Touchscreens Arrive
Smartphone touchscreens begin replacing physical keypads in consumer devices. Cash machines worldwide retain the physical 3×4 grid — its tactile reliability and accessibility making it the preferred standard for financial transactions.
Today
Still the Standard
Over 3 million cash machines operate globally, every one featuring the same layout. The arrangement of numbers and letters — seemingly arbitrary — follows a standard that has outlasted countless other input technologies.
How it works
Entering letters using a numeric keypad
Numeric keypads can represent any letter in the alphabet. Each key press corresponds to a letter group. Entering a sequence of digits produces a word when the digits are cross-referenced against the standard mapping.
- 1
Each digit key is assigned a fixed group of letters. The assignment follows the same sequence on every compliant device.
- 2
To spell a word, press the key that contains the first letter of each character in sequence — one key press per letter.
- 3
Predictive systems cross-reference the digit sequence against a dictionary to determine the most likely intended word.
- 4
On cash machines, this allows word-based PIN codes to be entered using only the numeric keypad, without additional hardware.
Example sequences
| Digit sequence | Key mapping | Word |
|---|---|---|
| 4663 | GHI · MNO · MNO · DEF | HOME |
| 2665 | ABC · MNO · MNO · JKL | BOOK |
| 7225 | PQRS · ABC · ABC · JKL | PACK |
| 3368 | DEF · DEF · MNO · TUV | FEET |
| 9673 | WXYZ · MNO · PQRS · DEF | WORD |
| 5683 | JKL · MNO · TUV · DEF | LOVE |
Common questions
Frequently asked questions
Why do cash machine keypads have letters alongside numbers?
The letters originate from the international telephone standard (ITU E.161), where each digit maps to a group of letters. This allows numeric codes to be remembered as words — for example, 5683 maps to LOVE — and supports alphanumeric entry on machines with only numeric keys.
Are the numbers and letters on cash machine keypads random?
What appears to be random cash machine keypad numbers and letters is in fact a deliberate international mapping: 2=ABC, 3=DEF, continuing through to 9=WXYZ. The 1, 0, *, and # keys carry no letters, a convention carried over from early telephony where those keys were reserved for operator use.
Can I use letters to remember my PIN?
Yes. Because the key-to-letter mapping is standardised, any four-letter word can be entered as a numeric PIN on any cash machine worldwide. Many customers find word-based codes easier to recall than arbitrary digit sequences.
Why is the layout different from a calculator?
Calculators place 7–8–9 at the top row; telephone and cash machine keypads place 1–2–3 at the top. The telephone layout was established by AT&T in 1963 for dialling efficiency. When cash machines adopted telephony-style keypads, they inherited this orientation.