Random serial number

The random serial number is the system Rolex adopted around 2010: a watch's serial number no longer follows a chronological sequence, and reading it no longer allows the example to be dated.

Before and after

Until the late 1980s, Rolex serial numbers were purely numerical and increasing. From 1987, the brand added a letter prefix that changed with the period; the last series of that system, around 2010, carry the letter G. These tables, published by many dealers, place a watch within a year or two, even though sources disagree on the exact changeover years. Since random numbers were adopted, that marker no longer exists: a scrambled eight-character number says nothing about the year. The number is also engraved on the rehaut, visible under the crystal at 6 o'clock, on watches produced from the mid-2000s.

Effect on value

For a watch with a random serial, the warranty card becomes the only reliable proof of the year of sale. This is one of the reasons the full set weighs so heavily in the value of recent Rolex: without a card, the buyer does not know whether the watch is two years old or twelve, and negotiates accordingly. The issue is particularly relevant for discontinued references such as the Explorer II 216570 or the Milgauss, where the production year is part of the appeal.

When buying, check that the engraved number is identical to the one on the card. When selling, hide it in published photos but keep it available for a serious buyer, as part of the authentication.