Longines Serial Numbers
Date your Longines from its serial — backed by the only brand archive that's free.
Longines has used one continuous, sequential serial-number series since the 1860s, applied to the movement and — on later watches — to the caseback. There's no embedded year code, so dating means matching the number to a production-year chart. Longines also has a standout advantage among the brands here: its St‑Imier archive will tell you the exact production date of any watch from its serial, often at no charge.
Enter your serial below for an estimate, then see the full chart and how to read it.
Find your Longines’s production year
Longines Serial Number Chart (1867–2000)
| Serial Number | Year |
|---|---|
| 40,400,000 | 2000 |
| 36,400,000 | 1995 |
| 32,400,000 | 1990 |
| 28,400,000 | 1985 |
| 24,400,000 | 1980 |
| 20,400,000 | 1975 |
| 16,400,000 | 1970 |
| 12,873,790 | 1966 |
| 11,211,988 | 1960 |
| 9,521,145 | 1955 |
| 7,915,750 | 1950 |
| 6,904,500 | 1945 |
| 5,950,000 | 1940 |
| 5,250,000 | 1934 |
| 4,250,000 | 1925 |
| 3,000,000 | 1913 |
| 2,100,000 | 1908 |
| 1,124,715 | 1900 |
| 500,000 | 1888 |
| 100,000 | 1875 |
| 20,000 | 1870 |
Serial milestones from the widely-reproduced movement-serial tables. Early figures (pre-1900) and post-1968 values are sparser and best treated as a guide; the St‑Imier archive can confirm any specific watch.
Where to Find Your Longines Serial Number
On vintage Longines the production serial is on the movement, engraved on a plate or bridge — and on very early calibers it can sit under the dial. You'll usually need to open the caseback (or have a watchmaker do it) to read it.
On more recent wristwatches an 8-digit serial appears on the outside of the caseback and is the number Longines references in its records. Pocket watches typically carry numbers inside the case back and on the movement.
From the mid-1940s a 4-digit reference number began appearing on case backs (often in the 5000–6000 range), identifying the model rather than the individual watch.
How to Read a Longines Serial Number
Longines serials are simple consecutive numbers — typically six to eight digits — that increase over time, with no embedded year code. You date a watch by matching the serial to a chart, then ideally confirming with the archive.
Anchors worth remembering: 100,000 is the mid-1870s, one million lands around 1900, ten million is the late 1950s, and the high-30-millions reach the late 1990s. Because the early series is sparse and the post-1968 figures are extrapolated, treat the chart as a practical guide and lean on St‑Imier for certainty.
Reference and Caliber Numbers
From the mid-1940s, Longines marked case backs with 4-digit reference numbers (commonly 5000–6000) identifying the case design and dial layout; many watches share one reference but each has its own serial. Later references became longer alphanumeric strings (e.g. L4.xxxxx) used for catalog and warranty identification.
Caliber designations — 13ZN, 30L, L990 and the like — are stamped on the movement and identify the movement family and architecture. The St‑Imier archive ties serial, caliber, and reference together to reconstruct a watch's original specification.
Frequently asked questions
Where is the serial number on a Longines watch?
On vintage pieces, on the movement (sometimes under the dial), so the caseback must be opened. On newer watches an 8-digit serial is engraved on the outside of the caseback.
Can Longines tell me exactly when my watch was made?
Yes — Longines maintains a full archive in St‑Imier and will provide the production date from your serial number, often free of charge. It's the most authoritative and accessible brand-dating service among major makers.
How accurate is dating a Longines by serial chart?
It's a good estimate, usually within a few years. The early (pre-1900) and post-1968 portions of the public charts are sparser, so confirm anything important with the St‑Imier archive.
What's the difference between the serial and the reference number?
The serial (on the movement, or the caseback on modern watches) dates the individual watch. The 4-digit reference identifies the model and case design and is shared across all examples of that model.