Short answer
IW323799 is an IWC reference number. It sits in the numbering block IWC uses across its Ingenieur line, and it turns up in search results far more often as a counterfeit listing than as a watch anyone actually owns. If the photos attached to the offer show a Submariner dial, a rotor stamped with the wrong brand, or a price under a couple hundred dollars, you already have your answer.
Two kinds of people search this term. People who were handed a watch and want to know if it is real, and people shopping for a copy. This is written for the first group. The second group usually learns the same lesson later.
What the reference number actually tells you
IWC reference numbers are not decoration. The digits describe case material, dial variant, bracelet configuration, and movement family. A seller who cannot explain the full number is reading it off a photo of a photo.
- Ask for the complete reference on the caseback and on the papers. They should match character for character.
- Ask which calibre is inside and whether the watch has ever been serviced.
- Ask for a movement photo through the display back, not a stock image from a listing.
If those answers come back vague, stop there. A real owner knows the reference by heart and produces documentation without being pushed.
Where copies give themselves away
- Caseback engraving that looks laser-etched and shallow, with uneven letter spacing.
- Dial printing that sits slightly raised under a loupe, or a logo that is not perfectly level.
- Date wheel sitting low or high in the aperture instead of centered.
- Crown action that grinds, or a crown that does not sit flush against the case.
- Bracelet end links that do not line up with the lugs, and screws with the wrong head shape.
- Crystal with weak or patchy anti-reflective coating.
- Lume applied unevenly, glowing a different shade from the hands to the markers.
- A generic automatic movement with no hacking seconds and the wrong beat rate.
Weight is the one thing photos never capture. A solid steel case and bracelet feels dense in the hand. Copies usually feel light and hollow, and the bracelet rattles.
Why the which factory question is a trap
Replica forums rank copies by factory codes and call the top tier a super clone. That vocabulary exists to sell watches. Even a well-made copy gets the movement architecture wrong, and no IWC service center will open it. There are no official parts behind it, and no watchmaker with an account at IWC is going to risk it for your watch anyway.
The legal and practical side in the US
Counterfeit watches are illegal to import and to sell in the United States. Customs can seize a shipment, and trafficking in counterfeit goods carries federal criminal exposure under 18 U.S.C. 2320. Past the legal risk, you get no warranty, no service, no replacement parts, and no resale market. A genuine watch can be sold when you are done with it. A counterfeit sits in a drawer until you throw it out.
How to check a genuine one
Take it to IWC or to a watchmaker with IWC parts access. They can open the case, read the movement, and match the reference against the serial. Buy from an authorized dealer, or from a pre-owned seller who offers the original box, papers, and service history. If the seller wants discretion, a wire transfer, or a meetup in a parking lot, that is not a deal, that is a warning.
Bottom line
Searching for this reference usually leads to the same place: a watch that is not an IWC, sold by someone who knows it. Treat the number as a starting point. Verify the movement and the paperwork, and walk away from anything you cannot inspect in person.