Short answer

IW938720 does not appear in IWC's published reference catalog. The format is correct for a modern IWC number: the letters IW plus six digits. The digits are not. IWC groups references by collection, and the 93xxxx block is not used for any documented series. Listings that carry this number come from replica sellers and marketplace sellers, not from IWC.

How IWC reference numbers work

Older IWC references used four digits, such as 3706 and 3714. Since the early 2000s the company writes IW plus six digits on the caseback, the papers and the service record. Examples: IW3270 for the Mark XVIII, IW3777 for the Pilot's Chronograph, IW5007 for the Portugieser Automatic.

A six-digit number is not free-form. It sits inside a block assigned to a collection. The 32xxxx and 37xxxx blocks cover pilot watches. The 50xxxx block covers larger Portugieser cases. The 93xxxx block is not in the catalog.

What IW938720 may be

Three options fit the evidence. First, a seller-generated SKU that mimics IWC formatting. Second, a mistyped reference, since 938720 resembles internal stock codes. Third, a fictitious number created for a listing photo.

No public record ties IW938720 to a caliber, a case size, a dial or a production year. Ask the seller for those four items. A real IWC listing carries all of them.

Checks that settle the question

  1. Caseback: reference, case number, movement caliber and material are engraved. Compare each item to the IWC catalog.
  2. Movement: in-house calibers carry an IWC code, such as 32111 or 69380.
  3. Papers: the reference on the warranty card must match the caseback.
  4. Service: IWC can confirm if a reference exists and if a case number was produced.
  5. Price: a current catalog model at 10 percent of retail is not a discount.

Legal note for US buyers

Trafficking in counterfeit goods is a federal offense under 18 U.S.C. 2320. U.S. Customs and Border Protection seizes counterfeit watches at ports of entry. A watch with no catalog reference is not a gray-market IWC. It is an unbranded item or a wrongly branded item.