The best way to make sure you own an authentic Cartier watch, of course, is to buy one from an authorised Cartier dealer. If you already have a Cartier, however, and would like to verify its authenticity, the easiest way is to make sure the serial numbers on the watch case and the accompanying warranty card match. You can also easily verify a Cartier watch's authenticity by having an authorised dealer inspect the it, but if this is not an option, there are other ways to verify the watch yourself.
Visit an authorised Cartier dealer with a watchmaker on the premises. Familiarise yourself with the various dress and sports models. Use a jeweller's loupe to inspect the watch. Have the watchmaker instruct you on the appearances of the Cartier logo, colour, the dial and the hands on the dial, according to Cartier.com.
Using the jeweller’s loupe, examine the case back. It will be signed "CC" or "Cartier" and have details such as its water resistance rating. Inspect the bracelet for the Cartier logo. Read the Cartier sales catalogue or brochure.
Inspect the movement by asking the seller to remove the case back to view it. The movement is a small electronic or spring-loaded mechanical device that operates the watch. The movement will have the Cartier name engraved on it. If the seller refuses the request, end your inspection and don't buy the watch.
Splash a small amount of water on the Cartier crystal. The watch should have a sapphire glass crystal and the water should bead upon contact. If the water smears, the crystal is not sapphire.
Inspect the Cartier polished cabochon stone on the crown. The stone should be set firmly in the crown and not glued. Examine the crown for glue traces.
Compare what you have examined in your physical inspection of Cartier watches with the sales literature. The watches you examined should match exactly the Cartier printed material. Counterfeit Cartiers more than likely will not have its name engraved on the movement. The hours, minutes and seconds hands may feature wrong styles. The Cartier logo on the dial will be printed not embossed. In some cases, the Cartier name may even be misspelled.
Ask for documentation for the Cartier watch you are considering purchasing. This is the most important component of the verification process. Ask the seller to show you the matching serial numbers on the warranty card and the case. No accurate verification can be made without the paperwork.
If you insist on purchasing a Cartier from an unauthorised dealer, do so only if the watch is accompanied with the warranty card. Verify the warranty card by asking an authorised dealer if he or she will honour it.
Never buy a Cartier from a flea market, an online auction or from a street vendor. Cartiers sell for upwards of £19,500. Purchasing the watch from unauthorised dealers is too risky.