How a UK driving licence number is made up

Every Great Britain driving licence carries a 16-character driver number that looks random but isn't. It is built, character by character, from the driver's surname, date of birth, sex and initials — which means you can read one, and sanity-check one, once you know the recipe.

The recipe, character by character

Take a licence number like MORGA 657054 SM9IJ:

Positions	Content	Example
1–5	First five letters of the surname, padded with 9s if shorter	`MORGA`
6	Decade digit of the birth year	`6` (the 1960s)
7–8	Birth month, with 50 added for women	`57` = July, female
9–10	Day of the month of birth	`05`
11	Final digit of the birth year	`4`
12–13	First letters of the first and middle names (9 if none)	`SM`
14	An arbitrary digit, almost always 9	`9`
15–16	Computer check characters	`IJ`

So MORGA 657054 SM9IJ decodes as: surname beginning Morga…, born July 1964, female, initials S. M.

The "+50 for women" rule

Positions 7–8 hold the birth month: 01–12 for men, 51–62 for women. A 03 is a man born in March; a 53 is a woman born in March. This is the best-known quirk of the format, and it has a practical use: if the digit pair is between 13 and 50 or above 62, the number is malformed.

Drivers who legally change gender are issued a new driver number, since the number itself encodes sex.

Surname quirks worth knowing

Short surnames are padded with 9s: Fox becomes FOX99.
Mac and Mc are both recorded as MC — MacDonald starts MCDON.
Apostrophes and hyphens are dropped: O'Brien starts OBRIE.
Only the surname at time of issue is encoded. A driver who married and changed name may hold a licence encoding their previous surname until it is renewed.

Why this matters for licence checking

The structure makes the number partly self-verifying. If a driver mistypes their number when giving consent for a check, the date-of-birth and surname segments usually stop matching, and a good checking system rejects it before wasting a check. It is also why the number is personal data twice over — it contains the holder's name, date of birth and sex by construction, so it should be stored encrypted and shared only where necessary.

Note this format applies to licences issued by DVLA for England, Scotland and Wales. Northern Ireland licences (issued by DVA) use an unrelated 8-digit serial with no encoded meaning.

The driver number alone doesn't tell you whether the licence is valid, revoked or disqualified, what categories it carries, or the penalty points on it — for that you need a DVLA check.