I’ve been in the watch business for over ten years, and in that time I’ve seen horrible fakes, decent fakes and fakes that Cartier itself couldn’t authenticate. Below well discuss how to authenticate most Cartier watches and go over some specific models.<br /> Cartier Authentication Guide <br />The First step when trying to Authenticate a Cartier watch is to make sure that they actually make the watch in question. Many of the fakes I have seen have dead giveaways, many times you'll see parts from different models compiled together, for example the watch case might be a copy of a one model yet the dial will be one from another. Cartier only makes certain models in precious metals, some examples are the Tortue, Tank-Americaine, Tonneau, Baignoire, if you encounter one if these models that isn’t made of a precious model then its time to run. I have very rarely seen fake Cartiers that were made of precious metals, that's why its important, to confirm the watch is made of the metal that it is hallmarked on the back case. I’ve seen many fakes that were hallmarked 750 (18k) that weren't actually gold; if you can confirm the watch is made of gold / platinum etc then it is probably authentic, though nothing is for certain and I advise you still do more verification.Please note though that Cartier makes many limited editions and just cause you cant find a certain model with a specific dial or function, etc, it does not automatically make it counterfeit, though be wary. Also it is popular to customize watches, for example putting a custom diamond bezel / dial etc on watches. So for example, Cartier doesn’t sell a Santos 100 in steel w/ a diamond bezel, though there are many around, if you encounter one it does not mean its counterfeit. Only up until a few years ago did Cartier start putting diamonds on its steel watches, I suppose they caved in because of pressure from brands like Rolex and Omega who have been doing it for years with much success.<br />Second step is to compare and contrast. Compare the watch in question with pictures of the watch from a reputable dealer. Pay very important attention to the dial and case back, from my experience this will eliminate most of the horrible and decent fakes. Make sure the case back looks the same, and the engravings on the back are consistent with the ones from the reputable dealer, also on the back of every Cartier watch from at least the last 20 years there is a 4 digit model code, for example, the code for a Mens Tank Rrancaise automatic in steel and steel & 18k is 2302, if you put into google “cartier 2302”, those models will pop up. If the 4 digit code on the back does not correspond to the model in question then its time to run. Please not though that sometimes the engravings on the back may differ very slightly (4 digit codes are always consistent), for example I’ve seen legitimate steel Tank Francaises that said “stainless steel” on the back case, and I’ve seen legitimate ones without it; as well I’ve seen certain two tone Cartier models that said “Stainless Steel” & “750” on the back and I’ve seen ones that only said “Stainless Steel”. I think this has to do with the production date.<br /> Cartier Authentication Guide <br />Last step is to open the watch up and compare the movement to one from a reputable site, make sure every bridge, wheel, screw, etc looks the same and is in the same exact position. This can be very deceiving though because Cartier used “ETA” Movements in many of their models (now they do in house movements, though I believe some models still use ETA Movement) and the good fakes will have the same exact Movement. ETA is a very large Swiss movement manufacturer and they provide movements to many of the top watch companies; you can buy many of their types of movements online. These specific models you have to be particularly careful with, 38mm Santos 100 in Stainless Steel, 34mm Santos 100 in stainless steel , 41mm Santos 100 Chronograph in stainless steel, Ballon Bleu 41mm in Stainless Steel. I’ve seen super clones of these models with correct ETA movements and Cartier rotors. Its my opinion there’s many of these super fakes are being traded by legitimate dealers, just because the fact you cant possibly tell 100%. Yes you could take it to Cartier and have the serial checked in the system, though many times the counterfeiter will put a authentic serial numbers on the case back. Sometimes if you put the serial # and the word Cartier into a Google search it will pop up on a counterfeit website, that's a good indication the watch is fake.<br /> Cartier Authentication Guide <br />If you complete all the steps above properly then you should be able to Authenticate most Cartier Watches.<br />