The short answer
If a listing for an IWC marked IW323790 is priced at a few hundred dollars, treat it as a counterfeit until a watchmaker proves otherwise. Two checks settle most cases in under a minute: whether the reference string resolves to a real cataloged IWC, and whether the caseback engraving is cut into the metal or printed on top of it. Copies fail one or both almost every time.
Start with the reference string, not the photos
IWC uses a fixed format. The letters IW, then four digits that identify the family and case, then a two-digit suffix for the material and dial variant. Counterfeit catalogs and marketplace listings mangle it constantly: IW 323790, IW-323790, 1W323790, or a suffix that never existed in the catalog. Those are listing typos, not rare variants.
So before you judge a dial, open IWC's own model database and search the number. A genuine reference comes back with a case size, a movement caliber, a dial layout, and a production era. If the number returns nothing, or the photos do not match what the catalog says that reference should look like, you are done. No further inspection needed.
What the caseback reveals
This is where most fakes give themselves away. On a real IWC of this generation the reference and case number are engraved into the metal, not printed on the surface. Under a loupe you see depth, a machined edge, and a slight burr at the end of each stroke. Counterfeits laser-etch or pad-print, which reads flat and grainy.
- Font weight and spacing between International Watch Co. and Schaffhausen.
- Reference and case number position relative to the caseback center and the lug line.
- Missing or duplicated Swiss Made text.
- Caseback screws with mismatched slot widths, a common shortcut on copies.
Photograph the caseback at an angle with a phone light. Engraving throws a shadow that print does not.
Movement, finishing, and beat rate
Ask for a movement photo before anything else. Genuine IWC automatics show perlage on the plates, Geneva stripes or circular graining where the caliber calls for it, blued or polished screws, and rotor engraving that matches the catalog. Movements found in this price band are Chinese or cloned, often dressed up with decorative bridge plates and a rotor stamped with text that does not match the reference.
Two specs to compare against the published caliber: the beat rate, which on most modern IWC automatics is 28,800 vibrations per hour, and the power reserve. If the seller cannot tell you the caliber, they do not have the watch.
Dial, hands, crystal
- Applied indices should be sharp, evenly set, and level with the dial.
- Lume plots should be filled to the same depth on every marker.
- Printed text should stay crisp at 10x, with no fuzzy edges or misaligned letters.
- Date wheels on genuine watches sit centered in the window. Copies ride high or low.
- Sapphire should carry anti-reflective coating on at least one side. Copies often ship with mineral glass and no coating.
Price, papers, and the part nobody mentions
A genuine watch at 5 or 10 percent of retail is not a deal, it is a counterfeit. Boxes and papers get faked too, so paperwork supports a story rather than proving one. The bigger issue is what you are left holding. Counterfeit shipments get seized by US Customs, IWC and its service partners will not touch a fake, and reselling one is trademark infringement with civil and criminal exposure.
If you want the look without the liability, homages and microbrands sell the same aesthetic legally, and they keep a resale value above zero.
Questions I would ask the seller
- Full reference and case number, in writing.
- A macro photo of the caseback and a photo of the movement.
- Service history, plus the name of the watchmaker who did the work.
- Return window and who pays return shipping.
- A payment method that leaves a paper trail.
A seller who will not send a movement photo has already answered the question.