Guides
Watch reference numbers, explained
A model name gets you into the right family. A reference number helps distinguish the version within it. That distinction matters when two watches look nearly identical.
Four names that do different jobs
Watchmakers do not all label their numbers the same way. Read a number in context rather than assuming every code on a watch is its catalogue reference.
- Brand: the watchmaker’s name.
- Model: a family or collection of watches.
- Reference: a code for a particular model or configuration, often shared by many watches.
- Serial: an identifier for an individual watch. A caliber identifies the movement, rather than necessarily the complete watch.
Start with the maker’s own information
Check the original paperwork or an official product page for the full reference. Keep letters, separators and suffixes intact when comparing it with a result.
An inscription on the case back can be useful, but it may describe the movement or case rather than the retail reference. Seiko’s instructions, for example, use the caliber code on the case back to find the appropriate manual.
Seiko: finding the caliber codeKnow what a dial photo cannot settle
Similar versions may differ in details that a front-facing photograph does not show. A changed strap, a reflection or an obscured date window can also make a comparison harder.
When the evidence is incomplete, keep the brand and model and leave the exact reference open. A precise-looking number is not useful if it points to the wrong watch.
Keep your Index accurate
Reference lets you correct the brand, model or reference after identification. Add another photo when it helps, and update the record as you learn more.
Identification describes which watch a result resembles. It does not establish whether an individual watch is genuine.