Free Tool
Cartier Serial Number Checker
Check an engraved Cartier serial against the formats Cartier is documented to use, and the size stamp against its production range.
Enter the engraving
On a Love or Juste un Clou bracelet the serial is engraved on the inner face, alongside the Cartier signature, the metal purity mark and the size. Examples: AB1234, 12345A.
A Cartier serial carries no date, and no public tool can look it up.
Unlike a Louis Vuitton date code, a Cartier serial identifies the individual piece in Cartier's own records, which are private. Anything claiming to return a production year from a Cartier serial is inventing it. A boutique can confirm a serial; this tool checks the format and the marks around it. Get a professional authentication →
Documented Serial Formats
Cartier serials are six characters mixing letters and digits. Engraving conventions have varied across decades of production, so a format mismatch is a reason to look harder rather than a verdict on its own.
The Marks That Should Accompany It
A serial on its own means little. On a genuine piece it sits in a set with the signature and the purity mark, all cut to the same standard.
| Mark | Meaning | What to look for |
|---|---|---|
| Cartier signature | The maker's mark, engraved not stamped. | Crisp and deeply cut on a genuine piece. Shallow, soft-edged or uneven lettering is a red flag on its own. |
| 750 | 18k gold — 75% gold content. | The standard for Cartier fine jewellery in gold. |
| 950 | Platinum. | Used on platinum pieces in place of the gold purity mark. |
| Serial number | Unique to the individual piece. | Never a style or reference number, and never repeated across pieces — though counterfeiters do reuse one valid-looking serial across thousands of fakes. |
| Size | Love and Juste un Clou bracelets are stamped 15 to 21. | A stamped size outside that range does not correspond to anything Cartier produces. |
Where the Serial Is Engraved
| Piece | Location |
|---|---|
| Love bracelet | Inner face of the band, alongside the signature, purity mark and size |
| Love ring | Inside the shank |
| Juste un Clou bracelet | Inner face of the nail head end |
| Trinity ring | Inside one of the three bands |
| Panthère / Tank watches | Case back, and often between the lugs |
| Santos watches | Case back, with the reference number |
Serial number, reference number, size — three different things
The serial is unique to your piece. The reference number identifies the model and is shared by every piece of that design. The size is the stamped number, 15 to 21 on a Love bracelet. Enter only the serial above; including the reference by mistake is the most common reason a genuine piece reads as the wrong length.
Want the full authentication guide?
Read how to authenticate a Cartier Love bracelet for the screw threads, weight, engraving depth and finish checks that catch fakes carrying a plausible serial.
Frequently asked questions
- Where is the serial number on a Cartier Love bracelet?
- Engraved on the inner face of the band, alongside the Cartier signature, the metal purity mark and the size. On a Love ring it is inside the shank; on Panthère and Tank watches it is on the case back, often with the reference number.
- Can a Cartier serial number tell you the production year?
- No. Cartier does not encode a date in its serials. The number identifies one individual piece in Cartier’s own records, and those records are private, so no public lookup can return a production year from a serial. Any tool claiming to do so is inventing the answer.
- What formats do Cartier serial numbers use?
- Cartier serials are six characters mixing letters and digits. The documented shapes are five digits followed by one letter (12345A), one letter followed by five digits (A12345), two letters followed by four digits (AB1234), and three letters followed by three digits (ABC123).
- What does 750 mean on a Cartier bracelet?
- 750 is the purity mark for 18k gold, meaning 75% gold content. Platinum pieces are marked 950 instead. Cartier fine jewellery is 18k gold or platinum, so a 585 (14k) mark on a piece presented as Cartier fine jewellery is out of place and worth questioning.
- What sizes do Cartier Love bracelets come in?
- Sizes 15 through 21, stamped next to the serial. A stamped size outside that range does not correspond to anything Cartier produces.
- Does a valid serial format mean my Cartier is authentic?
- No. Counterfeiters are known to reuse a single valid-looking serial across thousands of pieces, so a correct format proves only that the number is shaped the way a genuine one is. Cartier can confirm a serial through a boutique. A verdict otherwise needs the engraving depth and crispness, the screw threads, the weight and the finish examined together.
- What is the difference between a Cartier serial and a reference number?
- The serial is unique to your individual piece. The reference number identifies the model and is shared by every piece of that design. The size is a separate stamp again. Confusing the reference number for the serial is the most common reason a genuine piece appears to have a serial of the wrong length.