Short answer
If someone offers an IWC with reference IW329099 at a price far under the secondary market, assume it is fake until four things check out: the reference engraved on the caseback matches the papers, the dial and hands match the catalog photos, the movement is a genuine IWC caliber, and the serial traces to an authorized dealer. Nothing else settles the question.
What IW329099 is supposed to be
The 3290 block of IWC reference numbers belongs to the Aquatimer Automatic, a dive watch with an internal rotating bezel operated by a second crown at 4 o'clock. IWC does not build every number inside a family, so a reference can look plausible and still never have left the factory. Ask the seller for a photo of the caseback engraving before you discuss anything else.
Reference and caseback checks
- Photograph the caseback in daylight and read the engraved reference digit by digit.
- Compare those digits with the reference printed on the warranty card and the outer box label.
- Confirm the serial on the caseback is the same serial on the papers, with no sign of re-engraving.
- Send the serial to an IWC boutique or service center and ask them to confirm the model it belongs to.
Fake Aquatimers often carry a real reference with a serial pulled from another watch. When the two do not belong together, the boutique will say so.
Dial and hands
Genuine IWC dial print sits sharp and flat against the surface. On replicas the text looks thicker, the letters crowd the markers, and the lume plots sit slightly off center. Look at the date window: on the real watch it is crisp with even gaps at the edges. Look at the hands: IWC finishes them with clean bevels and no burrs. The second hand on a fake often sweeps with a visible stutter because the movement beats at a lower rate than the genuine caliber.
Case, bezel, and crown
Run a fingertip along the case flanks. The genuine case has a continuous brushed grain that changes direction only at defined edges. A replica usually shows a wavy grain, soft lug edges, and a crown that turns with grit. Rotate the inner bezel slowly. Genuine IWC bezels click with a firm, even detent at every position. A fake feels loose, mushy, or skips.
Movement
Ask for a photo of the movement through the caseback if the model has a display back, or ask the seller to have a watchmaker open it. Genuine IWC calibers carry engraved bridges, proper perlage, and a rotor with the correct logo and text. Replicas show stamped plates, poor finishing, and rotors that wobble when the case is shaken. A watchmaker can also measure the beat rate in seconds, which separates most copies from the real caliber.
Papers, box, and price
Genuine IWC packaging has consistent card stock, correct fonts, and a card that matches the watch. Blurry print, mismatched fonts, or a missing card are all warnings. Price is the last filter. If the asking price is a fraction of what the same reference sells for on the used market, the seller is not offering a bargain. Walk away.
If you already bought one
Stop wearing the watch. Contact the seller in writing and request a return. If that fails, take the watch to an IWC service center for a written assessment you can use in a dispute with your payment provider or card issuer.