Fake Cartier luxury watches: the short answer
A fake Cartier watch copies a Cartier design and carries the Cartier name without a license from Cartier. Cartier is owned by Richemont. Copies range from $20 street pieces to $800 "super clones". All of them infringe the Cartier trademark. Buying, importing, or reselling them in the US carries legal risk. Identification rests on four checks: caseback engraving, movement, weight, and paperwork.
What the markings should show
Genuine Cartier watches carry a case number and a serial number on the caseback. The case number is a 4-digit model reference, such as 3800 for a Tank. The serial is alphanumeric and unique to the piece. Engraving on a real Cartier is cut into the metal. On most fakes the text sits on the surface, feels raised under a fingernail, and the letter spacing is uneven. The "Cartier" script on the dial uses a set letterform. The two "r" characters and the loop of the "a" are distinct. Fakes often widen the script or place it off center.
Gold pieces add hallmarks. French-assayed gold carries the eagle head stamp for 18k. Swiss cases carry the St. Bernard dog head or the scale mark. Steel Cartier watches have no gold hallmark. A steel case with a gold stamp is a fake.
Movement and weight
Cartier uses in-house calibres in mechanical models and Swiss quartz in the Tank Must and some Tank Francaise references. A fake Tank often runs a Chinese quartz or a low-grade automatic. A real automatic winds and hacks. A cheap fake has a rotor that spins fast with a rattle. Weight tells more. A steel Cartier Tank Must weighs about 80 to 90 grams on the bracelet. A brass or pot-metal fake of the same size sits near 50 grams. Gold models differ more: 18k gold is about twice the density of steel.
Dial, crystal, and crown
Cartier uses sapphire crystal. A sapphire cabochon sits in the crown of most models. Fakes use mineral glass, acrylic, or a glass bead colored blue. Bead test: a drop of water beads on sapphire and spreads on glass. The crown on a real Cartier fits flush and is threaded on screw-down models. Fakes often show a gap.
Box, papers, and price
Cartier sells with a red box, a warranty card, and a booklet. A box alone proves nothing. Empty Cartier boxes sell online for $50 to $200. The warranty card holds a serial that matches the caseback. A mismatch means a swapped part or a fake. Price is the strongest signal. A new steel Cartier Tank Must quartz lists above $3,000 at an authorized dealer. Any offer far below that for a "new" piece with box and papers is a copy.
US law on counterfeit watches
Trafficking in counterfeit goods is a federal crime under 18 U.S.C. 2320. Penalties reach 10 years for a first offense and 20 years for a second, plus fines. Civil suits run under the Lanham Act, 15 U.S.C. 1114, and damages can be trebled. US Customs and Border Protection seizes and destroys counterfeit watches at the border. The personal-use exemption does not cover counterfeit goods. Resale platforms remove listings and can freeze seller accounts.
Repair and resale
Cartier service centers do not work on fakes and return them unrepaired. A fake has no auction market. Even watches sold as copies hold near-zero resale value because a buyer cannot verify parts.