Short answer
A fake IW9381201 is a replica of a watch sold under that IWC-style reference number. People search the term for two reasons. One is to check whether a watch already in their hands is genuine. The other is to buy a high-grade copy and avoid the junk. Both roads lead to the same checks. You verify the reference number first, then you look at the parts that cost money to reproduce well: case finishing, dial print, movement, and the hardware nobody bothers to photograph in a listing.
Read the reference before you read the watch
IWC reference numbers follow a house pattern, and they are published by the brand. That makes the string itself the cheapest test you have. The number in this keyword is longer than the format IWC normally uses on its current models, which is a reason to slow down rather than a verdict. Sellers mix, truncate, and invent references all the time, sometimes out of confusion and sometimes on purpose. Ask for a clear photo of the caseback engraving and of any card or booklet showing the same number. If the digits on the paperwork and the digits on the case do not match, stop there. No amount of nice photography fixes that.
Where a copy gives itself away
Start with the case. Look at the line where a brushed flank meets a polished bevel. On a good copy that line is crisp and runs straight. On a cheap one it wanders, or the polishing rounds off the edge into a soft blur. Run a fingernail along the lug tops. Sharp, even transitions are a sign somebody cared.
Then the dial. Print should sit flat and tight, with no fuzz on the edges of the text. Applied indices should be level and evenly spaced, and the lume fill should stop at the same height in every marker. The date wheel is a classic tell: wrong font, off-center numbers, or a window that sits a hair too low.
Hands deserve a loupe. Real ones are cut and finished, not stamped and left rough. Check the crystal too. Weak anti-reflective coating turns the dial into a mirror under a lamp, and that single flaw makes an otherwise decent watch look wrong from across a table.
The tiers you will actually see
- Budget copies. Stamped cases, mineral glass, a noisy quartz or a rough automatic. Fine as a beater, obvious in the hand.
- Mid tier. Solid stainless case, sapphire, a serviceable automatic. Finishing is decent at arm's length and vague up close.
- First copy. The top of the replica market. Correct case proportions, clean dial print, a decorated automatic with a plausible beat rate, and a bracelet that articulates without rattling. This is the tier worth paying for if you want the look without the price of the real thing.
Ask before you pay
- Which movement is inside, and what is its beat rate?
- Is the crystal sapphire, and is it coated on one side or two?
- Can you send a short video of the seconds hand and the date change?
- What is the measured case diameter and lug width?
- What happens if it arrives dead or badly finished?
A seller who answers all five without stalling is usually a seller who has handled the watch. Vague replies and stock photos are the norm on the other side of that line.
Keep your expectations honest
A first copy is a replica. It is not a genuine watch and it should never be sold or described as one. The movement will not be the manufacturer's in-house caliber, service support does not exist, and resale value is close to nothing. Buy it because you like how it wears on your wrist, not because you think it will hold value. That framing keeps the whole thing simple, and it keeps you from overpaying for a number on a listing.