How to find your watch’s reference number
“Submariner” or “Seamaster” isn’t enough to price, service or buy parts for a watch — there are dozens of versions of each. The reference number is what pins down exactly which one you have. Here’s where to look.
Short answer
Look in this order: the caseback, where many brands engrave the reference or a model code; between the lugs with the strap removed, which is where Rolex and Tudor put it; the warranty card, papers or original box; and the movement or case code printed on the back of Seiko and Casio watches. The reference identifies the model and is shared by every watch of that model. The serial identifies your individual watch. Keep the serial private when you post photos online.
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Reference number vs serial number
- Reference number (sometimes “model number”): identifies the model, including its case size, material, dial and bezel variant. Every watch of that exact model shares it. It’s what you search, what dealers price by, and what a watchmaker needs to order parts.
- Serial number: unique to your watch. It can date the watch, it links it to its papers, and it’s what police and insurers record if a watch is stolen.
Blur or crop out the serial when you post photos on forums or marketplaces. The reference is fine to share.
Where to look
1. The caseback
Turn the watch over. Many watches engrave or print the reference, a model code or a case number on the back, often alongside “stainless steel”, the water resistance and “Swiss made”. On a see-through (exhibition) caseback, the numbers may be on the ring around the glass. Worn engravings read better under a raking light, such as a torch held almost flat to the surface. What the other caseback markings mean.
2. Between the lugs
Some brands engrave between the lugs, the horns the strap attaches to. You only see these numbers with the bracelet or strap removed, which is best done by a watchmaker if you don’t have a spring-bar tool. While the strap is off, it’s the right moment to measure the lug width if you’re thinking about a replacement. Rolex and Tudor are the best-known examples: traditionally the reference is between the lugs at 12 o’clock and the serial at 6 o’clock.
3. The rehaut (inner bezel ring)
On many modern Rolex watches the serial is engraved on the rehaut, the angled ring between the dial and the crystal, visible at the 6 o’clock position. Other brands use this spot for engraved branding rather than numbers.
4. The papers and box
Warranty cards, certificates, original receipts, service papers, even a sticker on the box or the swing tag often list the reference and serial. If you have papers, they’re the easiest source. Check the serial on the papers matches the watch.
5. Inside the watch
Some older watches carry reference or case numbers inside the caseback, and serials on the movement. Opening a case can damage the gaskets and water resistance, so leave this to a watchmaker.
How some common brands mark their watches
| Brand | Where to look | What it looks like |
|---|---|---|
| Rolex, Tudor | Between the lugs (strap off); modern Rolex serial on the rehaut | Reference such as 126610LN; the caseback is usually plain |
| Omega | Caseback, papers; the full reference is on the warranty card | Long references such as 210.30.42.20.01.001; serial on the case or movement |
| Seiko | Caseback | A movement–case code such as 7S26-0020, plus a serial whose first digits encode the year and month. The retail model code (like SKX007) is often on the box or tag, not the watch |
| Casio | Caseback | A model name such as GA-2100 and a module number (often in a small box), which matches the manual |
| Fashion and department-store brands | Caseback | A model or style code, often starting with letters (e.g. FS…, AR…, MK…) |
Conventions vary by era and model; this is where to start looking, not a rule. Brands change where they engrave, and a replaced caseback can carry numbers from another watch.
Still can’t find it?
- Identify the model from the dial first. Brand name, the text on the dial, the bezel, the date window and the hands narrow it down fast, and then the reference is a search away. See how to identify a watch from a photo.
- Ask a watchmaker or an authorised dealer. They can remove the bracelet or open the case safely and read what’s there.
- Ask a brand-specific forum with clear photos of the dial, the caseback and the movement if visible.
No reference in sight? Start with a photo
Loupe identifies the brand, model and, when it can see enough, the reference from a photo of the dial, with a confidence rating on every result. When it isn’t sure, it lists the likely alternatives and suggests photographing the caseback. Free trial, cancel in Google Play.
