LONGINES SERIAL NUMBER GUIDE

Longines serial numbers

Longines is notable among watch brands for maintaining comprehensive historical records, including serial number databases that can often be used to date watches with considerable precision. The serial number on a Longines watch is typically found on the movement and can be looked up through Longines' archives to determine the production year. This archival access is commonly considered one of the best dating resources available for any watch brand.

The movement serial number on vintage Longines watches is usually engraved on the movement itself, which requires removing the case back to access. The case back may carry a separate case number or reference, but it is the movement serial that is typically most useful for dating through Longines' records. Serial number tables compiled by collectors also exist and can provide approximate dating without needing to contact Longines directly.

Modern Longines watches include reference numbers on the case back that identify the model, along with the caliber designation. These reference numbers, typically in a format like 'L3.742.4.56.6', encode information about the model line and specifications. The brand's customer service and authorized service centers can often provide production information based on these reference numbers. Longines' heritage museum in Saint-Imier is also a valuable resource for historical inquiries.

#01

What This Usually Means

A serial number on a Longines watch is primarily used to identify the production batch, manufacturing date, or individual unit. It can help you determine when the watch was made, verify its authenticity against brand records, and track service history. Different formats may indicate different eras of production.

#02

Where to Find It

On most Longines watches, the serial number can be found in one or more of the following locations: engraved on the case back (sometimes visible without removing it), stamped between the lugs at the 6 o'clock or 12 o'clock side (requires removing the bracelet or strap), or engraved on the movement itself (requires opening the case back). Vintage models may have the number in different locations than current production models.

#03

Common Variations

Serial number formats for Longines watches have changed over the years. Earlier models may use purely numeric sequences, while newer models might include letter prefixes or suffixes indicating the production year, factory, or market. Some limited editions use separate numbering schemes (e.g., "0042/1000"). Always compare the format you find against known references for the specific model and era.

More Longines Guides

Case Back Markings Bracelet & Clasp Codes Production Years Identify Your Watch

Related Markings

Deployment Clasp Marking

Markings found on a deployment (deployant) clasp that identify the clasp type, size, and brand. These help determine compatibility when replacing or servicing the clasp mechanism.

Case Reference Number

A manufacturer-assigned reference number identifying the specific watch case design, dimensions, and material. This is the primary identifier for sourcing correct case parts and compatible accessories.

Crown Logo Stamp

A brand logo or emblem stamped or engraved on the watch crown. This identifies the manufacturer and can indicate whether the crown is an original or replacement part.

Movement Country of Origin

A marking indicating where the watch movement was manufactured, such as "Swiss" or "Japan." This identifies the movement's origin, which often influences perceived quality and value.

Swiss Made Label

A legally protected designation indicating the watch meets Swiss origin requirements for movement, assembly, and quality inspection. "Swiss Made" is one of the most recognized quality marks in watchmaking.

German Made Marking

A marking indicating the watch was manufactured in Germany, typically associated with brands from the Glashutte or Pforzheim watchmaking regions. German watches are known for Bauhaus design and engineering precision.

Frequently asked questions

Where is the serial number on a Longines watch?

The primary serial number on a Longines watch is typically engraved on the movement itself, which requires removing the case back to access. The case back may carry a separate case reference number. Having a qualified watchmaker open the case is commonly recommended to avoid damaging the watch and to ensure the movement is handled properly.