Short answer
Fake Cartier Tank 8240029 is a search string, not a watch model. Cartier reference numbers for the Tank family start with letters: W5200005, WSTA0041, WGTA0011. A seven digit string such as 8240029 belongs to a marketplace listing, a seller stock number, or an auction lot. The number alone proves nothing about the watch. Use the case, the dial, the movement, the case back engraving, and the papers to reach a conclusion.
Where the number 8240029 comes from
Marketplace item numbers, pawn shop tags, and wholesale stock lists use plain digit strings. The origin of this exact number is not public. If a seller quotes 8240029 as a Cartier reference, that claim is false. Ask for the reference on the case back and for a clear photo of the engraving.
Real Tank references
Cartier uses a set of reference formats across the Tank line.
- Tank Solo large steel quartz: W5200005
- Tank Must large steel quartz: WSTA0041
- Tank Francaise large steel quartz: WSTA0005
- Tank Louis Cartier yellow gold, hand wound: WGTA0011
Gold Cartier cases carry precious metal hallmarks. Steel cases do not.
Checks on a suspect Tank
Case and crown
The Tank case has straight sides and a flat profile. The crown sits on the right side and holds a blue cabochon. Cartier fits synthetic spinel to steel and sapphire to gold. Copies often use plastic or glass, or omit the stone. Case back engraving is cut into the metal, not printed. Look for the reference, the serial, the Swiss Made stamp, and the hallmark on gold pieces.
Dial
Genuine dials show a railway minute track and Roman numerals with even spacing. The word Cartier is printed, not raised. Some models hide a secret signature inside the VII or the X. Print edges on copies smear under a 10x loupe.
Movement
Match the movement to the reference. Quartz Tanks run on a battery. Mechanical Tanks wind by hand or by rotor. A seller who cannot state the movement type is a risk. Have a watchmaker open the case back.
Papers and serial
Cartier warranty cards list the reference and the serial, and they carry a dealer stamp. The serial on the card matches the case back. Fake sets show numbers that do not match, or a serial that repeats across listings.
Price signals
Steel quartz Tanks list in the low thousands of US dollars. Gold Tank Louis Cartier models list higher. A price far under the used market points to a fake, a stolen watch, or a watch with a swapped movement.
Legal position
Sale of counterfeit trademark goods is illegal in the US. US Customs and Border Protection can seize shipments, and the buyer loses the money. A listing that hides behind a stock number such as 8240029 leaves no recourse.