Short answer
IW938989 is not a reference number that IWC Schaffhausen publishes. IWC reference numbers use the format IW followed by six digits. The number 938989 does not match any known IWC family. A listing that calls a watch IW938989 is mislabeled, invented, or counterfeit.
How IWC reference numbers work
IWC prints the reference on the caseback, on the warranty card and in the catalog. Older references use four or five digits, such as 3706 or 3714. Modern references use six digits after the IW prefix. Collectors group them by family:
- IW32xxxx: ETA-based automatics, entry models
- IW37xxxx: Pilot's Watch chronographs
- IW39xxxx: Pilot's Watch and Ingenieur lines
- IW50xxxx: Portugieser and in-house automatics
- IW69xxxx and IW82xxxx: newer in-house calibers
No IWC family starts with 93. That is the first sign.
Caseback checks
Genuine engraving sits in the metal. It has crisp edges and even depth. Laser etching on replicas looks shallow, fuzzy or painted. The reference and the serial must appear together. On older watches the reference is stamped inside the caseback, not outside.
Movement checks
IWC uses in-house calibers in the 52000, 69000, 82000 and 89000 families, and ETA-based calibers in the 30000 range. A seller who shows a rotor marked with a caliber that does not exist in the IWC line is selling a fake. Ask for a photo of the movement and the balance wheel.
Papers, box and serial
Serial numbers run six and seven digits. IWC has no public serial database, so a dealer or a service center has to confirm the number. Warranty cards carry the reference, the serial and the date of sale. A card with a reference that IWC never made has no value.
Price signals
Most steel IWC models list between $5,000 and $13,000. A new watch at $400 is not an IWC. A used watch far below market price is a warning, not a bargain.
If the reference cannot be found in IWC's catalog or in a dealer's system, treat the watch as fake.