Datation Montre Omega

A Brief Explanation of the Rolex Serial Numbering System...

Around this same time, Rolex had initiated another dating system--They stamped the inside of the case back with a code consisting of a Roman numeral and two numbers. The Roman numerals were I, II, III, IV, which represented which quarter of the year the watch was produced. The numbers simply represented the two-digit year in which the watch was produced. Therefore, the code 'III 53' would represent the 3^rd quarter (i.e. July-September) of 1953--this code continued until around 1970. Please note, some examples (primarily from around 1959), did feature the Roman Numeral and a 4-digit year (i.e. 'ii 1959').

In the early 1960s, Rolex once again reached the 999,999 mark, but this time added a 7^th digit and continued into the 'millions' until mid 1987, when the numbering reached 9,999,999. At this time, Rolex elected to start numbering with a letter prefix (e.g. R000001).

The system started with the letter 'R', whcih was then subsequently followed by L-E-X. Thus spelling out the word 'ROLEX' with the 'O' being omitted, to help avert any possible confusion with the number '0'. This sequence continued through November 1991, when a new numbering system was introduced utilizing the letters N, C and S, which took them through 1993. In 1994, Rolex started yet another sequence with the letters: W, T and U, then A, P, and K in subsequent years, followed by Y, F, D, Z, M, V and then G in 2010.

Please note, during the 1990s and 2000s, it is estimated that Rolex produced around around 1 million watches per year. Coincidentally, the numbering sequence of any particular Letter from this system (e.g. V000001 to V999999), would in fact also be 1 million serial numbers, and worked well with this system. It is worth mentioning that Rolex would not cease a letter prefix run at the end of a given calendar year, but would continue a letter run until all numbers were used before changing the prefix code. Therefore, letter prefixes could end at random times of the year, and did not start or stop at the beginning or end of a calendar year.

Then, later in 2010, they scrapped the entire system and implemented a brand new 'Random' numbering system, in which each watch is issued a (unique) 8-digit 'Random' number consisting of numbers and letters. An example of this number would be something like '16G9L7F4' and could start with either a letter or number. This offers them a seemingly endless numbering system by which they could continue indefinitely. Figuring 8 digits with a possible 36 characters (26 letters and 10 numbers) per digit, gives them over 2 Trillion (2,821,109,907,456 to be exact) possible serial numbers. Even if they were to omit the letters 'O' and 'I', to help avert any possible confusion with the numbers '0' and '1' (as they did in the previous numbering system), that would still give them 1,785,793,904,896 possible combinations. While this

This also offers Rolex an opportunity to keep the exact year of manufacture for any particular watch a secret. Something that has come back to haunt them for some time now. Therefore, only Rolex knows exactly when any particular watch was made and they aren't talking.

The following 'Round Numbers' Serial Number List has been comprised of known serial number ranges for the years listed. By checking a particular serial number against this list you should be able to date a watch with reasonable accuracy. However, it is no quarantee as to when your watch was shipped from the factory. Furthermore, this list only applies to Rolex Oyster-cased watches, and should NOT be used for Tudor, or vintage non-Oyster Rolex watches.

A Tudor (work in progress) Serial Number List is included at the bottom of this page...


The numbers listed (particularly those preceding the letter prefix system) are a 'middle number' for the given year. As an example, the year 1944 listed below shows a serial number range of 270000, but this year could include serial numbers below and above this number (i.e. 260000-280000). This is simply the median number represented for that year.

Please Note: John E. Brozek, InfoQuest Publishing, Inc. and this website are in no way associated with Rolex USA, nor any of its associated companies. John E. Brozek does not now, nor has he EVER worked for the Rolex Watch Company or any of its subsidiaries. The information provided on this page is solely the work of the author and has not been reviewed or authorized by Rolex USA. Furthermore, the publishers have received no help from Rolex USA, nor any of its associated companies or any serving employees.

Also started engraving the serial number inside the bezel (under the crystal)

(Now features 8-digits instead of 7)