Short answer
IW938105 is a reference number that appears in replica watch listings. IWC Schaffhausen does not publish it in its online catalog. The format copies IWC house style: the letters "IW" plus six digits. A number that follows the pattern still needs three things to be real: a catalog page, a spec sheet, and a serial number range. Without those, the reference is unverified.
How IWC reference numbers work
IWC stamps "IW" on current references and adds six digits. Older models use four digits, such as 3714 for the Portugieser Chronograph. The first two digits point to a watch family. The last digits point to case metal, dial color, and strap. The Portugieser Automatic 42 is IW500703. The Pilot's Watch Mark XVIII is IW327001. IW938105 does not sit in a live IWC family. Current families are Pilot's Watches, Portugieser, Portofino, Ingenieur, Aquatimer, and Da Vinci.
Why listings use this number
Replica sellers need a number that looks correct. They copy the "IW" prefix and add digits. A search returns one or two sales pages and no catalog entry. Many of those pages use terms such as "Swiss movement" or "1:1 clone." Those terms have no standard definition. Photos in this price band often show an ETA or Sellita movement, or a plain rotor with no caliber mark. Case sizes in the listings run from 40 mm to 42 mm and do not match an IWC spec sheet.
Checks that settle the question
- Search the IWC catalog. If the number returns nothing, treat it as unverified.
- Ask for a photo of the case back. Real IWC case backs carry the reference, the serial number, and the caliber.
- Send the serial number to an IWC service center. IWC confirms serials for a fee.
- Compare price. Genuine Portugieser and Pilot's models sell from $4,000 to $25,000. Replica listings run $150 to $600.
- Read the warranty card. A real card matches the serial, the model, and the dealer name.
Legal position in the United States
18 U.S.C. § 2320 makes trafficking in counterfeit goods a federal crime. A first offense carries up to 10 years in prison and a fine under Title 18. A repeat offense carries up to 20 years. U.S. Customs and Border Protection seizes counterfeit watches at ports of entry. Watches and jewelry rank among the top seized categories in CBP reports. An imported counterfeit watch can be seized with no refund and no return.
What the number does not tell you
IW938105 gives no information about movement, case material, water resistance, or production year. Buyers who need those details for a genuine watch can request an extract from the IWC archives. That document lists the date of sale, the case material, and the movement. No such record exists for a number that was never produced.