How to check a watch serial number
A serial number identifies one watch. On some brands it also points to the production era, and it is the number the brand's own records use for the warranty date, the factory configuration and any stolen report. Below is where to find it on each brand and what you can check for free.
No brand publishes a public serial lookup, and a valid serial alone does not prove a watch is genuine, so treat it as one step in the check.
Last updated October 2026 · Reviewed by Nazar Moda, Managing Partner
Can you check a watch serial number yourself?
Serial number vs reference number
The reference number is the model. The serial number is this one watch. Check the serial, and use the reference to confirm the watch is the model it claims to be.
Two identical watches off the same line share a reference. It tells you what the watch is, not when it was made or whether yours is the genuine one. On a Rolex made before about 2005 it is engraved at 12 o'clock, opposite the serial at 6 o'clock.
A genuine serial belongs to exactly one watch, and the brand's records hang off it. On some brands it also hints at a year. Rolex and Cartier stopped encoding the year around 2010, so on a modern watch the number alone gives you no date.
Where to find the serial number
Each brand engraves the number in its own spot. It is small, so use a loupe or a phone camera zoomed in.
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Rolex
Between the lugs, or on the rehaut
Look between the lugs at 6 o'clock, or on the rehaut, the inner ring between the dial and the crystal. Which one depends on the year, and our Rolex serial number guide has the dates.
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Audemars Piguet
On the back
The number is engraved on the back of the watch. An AP also carries a separate movement number, which our Audemars Piguet guide explains.
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Patek Philippe
On the movement
The number is engraved on the movement inside the watch, so a watchmaker usually has to open it. It is also on the warranty card or papers if you have them. See our Patek Philippe guide.
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Omega
On the back lug
The number is engraved on the back lug of the watch.
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Vacheron Constantin
On the back
The number is engraved on the back of the watch.
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Cartier
Usually the caseback
Cartier engraves the serial into the metal, usually on the caseback and on some references between the lugs. A serial on a sticker, or no serial at all, is a common sign of a fake. Our Cartier guide has the details.
Can you check a watch serial number for free?
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Rolex: a free year estimate
The free lookup on our Rolex serial number page turns a serial into an approximate production year. Rolex doesn't publish production dates, so read the result as a range.
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Cartier, Audemars Piguet and Patek Philippe: how the serial reads
Our Cartier, Audemars Piguet and Patek Philippe guides explain how each brand's numbers work. Older numeric Cartier serials hint at a year, an AP series letter gives a rough period, and a Patek movement number gives an approximate year. All three are estimates.
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No brand has a public lookup
A free chart or tool can estimate a year, but it can't show you what the brand has on file. That record sits in the brand's own database.
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The full check is paid
A serial check runs the number through the brand's database and returns the factory record: warranty date, factory dial and bracelet, movement serial and stolen-report status. A stolen watch can carry a valid serial, so a year chart won't flag it, but the stolen-report status in the brand's record can. On watches older than about ten years the brand no longer returns an exact warranty date, so the report covers the factory configuration and stolen status instead.
What a clean serial does and doesn't prove
A serial that matches the brand's format and the watch's era is a good sign, but counterfeiters engrave real serial numbers on fake cases, so it does not prove the watch is genuine.
A reliable check runs the number against the brand's records and puts the watch itself under a loupe. Our guide on how to spot a fake Rolex covers the red flags on the number and the clasp code.
Pick your brand
The paid check covers six brands: Rolex, Audemars Piguet, Patek Philippe, Richard Mille, Cartier and Vacheron Constantin. Prices and the full brand list are on the serial check page.
Want the brand's own record? We'll run the serial.
Send us the brand and the serial number and we run it through the brand's own records. If you have a question first, text us at (605) 521-2821.