A quick answer first: IW93820 is not a reference you will find in IWC's own catalogue. The string shows up almost only in replica listings, where sellers use it as a factory or case code for an IWC-style watch. Treat it as a listing label, not as proof that the watch tracks a real Schaffhausen model.
Where the number comes from
IWC reference numbers follow a simple pattern: the letters IW, then four or five digits. That pattern is easy to copy, and rep sellers lean on it. A dealer can take a case that a factory already sells under an internal code, slap an IW prefix on it, and the result reads like an official model number to anyone who does not know the catalogue. I have seen the same case advertised under two or three different codes by different sellers, which tells you the number is marketing, not engineering.
Some codes trace back to a specific factory batch. Others get recycled or invented when a listing is refreshed. So two watches sold as "IW93820" may differ in movement, case thickness, dial finish, and bracelet supplier. The code tells you almost nothing on its own.
How to verify a reference number
The manufacturer's site and its published catalogue are the only places a reference is confirmed. If the number is missing there, no amount of forum confidence makes it real. Independent marketplaces and auction archives are the next best check. Search the exact string, look at what comes back, and note whether the results are dealer listings or documented models.
One more test: compare the specs. A real reference has a published diameter, thickness, movement, and water resistance. If nobody can tell you those numbers for the watch in front of you, the code is doing work it should not be doing.
What to judge instead of the code
The code is a distraction. These are the things that decide whether a watch is worth the asking price.
- Movement: which base it uses, beat rate, stated power reserve, and whether the finishing is machined or hand-applied.
- Case: diameter and thickness in millimeters, lug width, crown size, and how the lugs meet the strap.
- Dial: font weight, date wheel alignment in the window, lume application, and index polish.
- Case back: depth of engraving, quality of the reference and serial stamping, and whether the lettering is crisp or soft.
- Bracelet or strap: end-link fit, clasp engraving, and the spring bars that come with it.
Red flags in a listing
Photos with no movement shot. A price far below what the named factory normally charges. Stock images with visible watermarks. A refusal to send a fresh photo with a timestamp. Urgency language about a limited batch. Any of those on their own is a warning; three together is a pass.
Questions worth asking before you buy
- Which factory made it, and what is the exact model name?
- Which movement is inside, and can you send a photo with the case back off?
- What are the case dimensions in millimeters?
- What happens if the watch arrives with a fault?
Bottom line
IW93820 is a seller's label, and treating it as an official IWC reference leads to bad decisions. Ask about the movement, the case specs, and the factory. Buy the watch in the photos, not the number in the title.