Short answer
IW323758 is a genuine IWC reference number, and that is exactly why counterfeiters print it on fake watches. The number on the caseback proves nothing on its own. To judge an IW323758 you have to verify the case, the dial, the movement, the serial number and the paperwork as a set. If any one of those does not line up with IWC records, walk away.
What the reference means
IWC reference numbers combine a case family with a variant code. In IW323758, 3237 identifies the case family and 58 identifies the version: case metal, dial colour, and whether the watch left the factory on a strap or a bracelet. Two watches can share the 3237 family and differ in every visible detail. Before you compare a suspect watch to photos online, confirm the correct configuration for reference 323758 from IWC or a reputable reference database. Most "this looks wrong" arguments start because a buyer compared one production variant to another.
Fast checks that catch most fakes
- Caseback engraving: laser engraving on genuine IWC cases is shallow and crisp. Fake engraving is often deeper, with rounded letter edges and uneven spacing.
- Dial printing: text should stay sharp at 10x magnification. Blurry script or a rough date window edge is common on counterfeits.
- Serial and reference pairing: the serial should fall inside the correct production range for that reference.
- Hands and markers: check length, finish and lume fill under a loupe. Genuine hands reach the printed track exactly.
- Movement finishing: striping, perlage and engraving should be consistent and machine-sharp, not stamped or painted.
Step-by-step authentication
- Photograph the caseback in flat light and read the full reference and serial number.
- Compare both numbers against IWC service records or the reference data for the 3237 family.
- Check the serial range against the production years listed for that reference.
- Measure the case with callipers and compare the result to published dimensions.
- Weigh the watch. Counterfeit cases use lower-density alloys and often weigh several grams less.
- Open the caseback and record the calibre number stamped on the movement.
- Match that calibre to the movement IWC lists for reference IW323758.
- Inspect the crown and bezel or pusher action for correct thread pitch, click and alignment.
- Examine the bracelet or strap: end-link fit, clasp engraving and screw heads.
- Verify the box, warranty card and receipt numbers against the watch itself.
Red flags in listings
- Price far below the market range for the reference.
- Low-resolution or watermarked photos, or images reused from another seller.
- Seller refuses a caseback photo or an in-person inspection.
- Warranty card with a mismatched serial or a blank purchase date.
- "New old stock" claims with no service history on a watch over ten years old.
Where to get a real opinion
An authorised IWC service centre can verify the reference and serial against manufacturer records and will quote any needed service at the same time. Independent watchmakers who service Swiss automatics can also open the watch and identify the movement. Either route gives you a written opinion you can use to cancel a sale or open a dispute.
Price and provenance
Use completed sale prices, not asking prices, to set your range. A genuine IW323758 with a full set sells inside a defined band, and anything well under that band is usually damaged, stolen or fake. Provenance matters as much as the watch: original box, stamped card, service receipts and a traceable seller identity all reduce risk. If the seller cannot provide a history, treat the watch as unverified no matter how good the photos look.