Short answer
A fake Must de Cartier Tank is a counterfeit of one of two watches that share almost the same name. The first is the vintage Must de Cartier Tank, a gold plated vermeil watch Cartier sold from the 1970s into the 1990s with lacquer dials. The second is the Tank Must, the steel quartz watch Cartier brought back in 2021. Both get copied hard, and the copies fail in different places. If you are judging a watch from photos, decide first which of the two you are looking at. Then check the handful of details a counterfeiter has to nail and usually does not.
Two watches, one confusing name
People mix these up constantly, and that confusion is exactly what sellers of fakes lean on. A vintage Must de Cartier is a vermeil watch. Vermeil means sterling silver underneath with a thick gold plating, and the good examples carry French precious metal hallmarks plus a plating mark. Dials came in burgundy, blue, black and ivory lacquer, and the sizes ran small, often around 23 by 30 mm on the men's models.
The modern Tank Must is a different animal. Steel case, quartz movement, and two main sizes, roughly 29.5 by 22 mm and 33.7 by 25.5 mm. Steel versions use a blue spinel cabochon on the crown, not a sapphire. There is also a SolarBeat version with no battery, and Cartier has hidden its signature inside the numeral VII on some Tank dials. Know which generation you are buying before you judge anything else.
Vintage vermeil specifics
This is where most of the fakes live, because the real ones were affordable and sold in huge numbers, so the market is flooded. Real vermeil has depth to the plating that you can see at the lug edges, and the hallmarks are crisp and shallow. Stamps punched into a base metal case that feels light and rings hollow are the classic tell. Plating wear is normal on a 40 year old watch. Plating that has flaked off in sheets is not.
Where copies give themselves away
- Case and finish. Real Tank cases have sharp, straight brancards and clean lug transitions. Fakes round those corners off, and the polishing looks soft rather than crisp.
- Dial lacquer and print. Genuine lacquer has depth and a slight gloss. Fake dials look flat, and the printing on the minute track and the Cartier name is thick or slightly doubled.
- Crown and cabochon. The stone should be faceted, evenly set and the right shade. Glued glass or plastic, a wobbly setting, or a crown that sits too proud are all common.
- Movement. The modern Tank Must is quartz, but it should be a clean, quiet Swiss quartz. Cheap copies tick loudly, and the seconds hand stutters instead of stepping once per second.
- Caseback stamps. Reference and serial numbers should be consistent, evenly struck and match the case. Mismatched fonts and numbers that appear on ten different listings online are a red flag.
- Strap and hardware. Original straps and deployants have tidy stitching and correct tang shapes. Aftermarket parts are not proof of a fake by themselves, but they often travel with one.
Checks that take two minutes
- Search the serial number. If it shows up on multiple listings in different countries, walk away.
- Look at the dial print under magnification. Any blurriness in the numerals is a problem.
- Weigh it in your hand if you can. Vermeil and steel both feel denser than the pot metal copies.
- Ask for a photo of the caseback and the inside of the caseback. Sellers of fakes rarely have both.
- Ask about service history. Genuine owners usually know where it was last serviced.
What photos hide
Photos hide weight, plating wear at the edges, and the movement itself, which are the three things I lean on most. If a listing only shows the watch from the front, that is not an accident. Ask directly, and treat evasive answers as the answer.
The legal side in the US
Trafficking in counterfeit goods is illegal in the United States, and customs can seize shipments. Buying one for yourself carries risk too, since there is no warranty, no service support from Cartier, and resale can expose you to liability. A counterfeit is not a cheaper version of the same watch. It is a different object that happens to look similar in a photo.
Bottom line
Find out which Tank you are looking at, then check the case, the dial print, the crown and the caseback stamps. Most fakes fail at least two of those. When a deal looks too good for a steel quartz Cartier, it usually is.