Short answer
A watch sold as an IWC Ingenieur IW3211 is fake when the case number, the movement finish, or the dial print does not match IWC records. Ask for a photo of the caseback engraving and a photo of the movement before you pay. Confirm the reference with IWC. Photos alone are not proof.
Check the reference first
IWC stamps a case number on the caseback and a serial number on the movement. Both numbers appear on the warranty card and on the box label. Public reference lists for the Ingenieur line cover the 666 from 1955, the 866, the 1832 from 1976, the 3508, the 3521, the 3227 and the 3239. The number IW3211 does not appear in most of those lists. Treat that as a question, not a verdict. Ask the seller for the case number and send it to IWC. IWC runs an archive extract service that confirms model and production year for a fee.
Case and bezel
Look at the lug tops. Ingenieur lugs have flat tops and sharp inner edges. Fakes show rounded edges and soft polishing. On Genta-era models the bezel holds five screws. Each screw sits in a recess with a flat bottom. Fakes use screws that sit high or sit off center. Case thickness is a common mismatch. Ask for caliper readings of diameter and thickness.
Dial
Use a loupe at 10x. Dials from IWC show applied markers with beveled edges and no glue at the base. The date window has sharp corners and a flat inner wall. Printing has solid edges. Fakes show uneven letter spacing in "Ingenieur", a wide date font, and markers that sit high or tilt.
Movement
Ask for a clear photo through the caseback. IWC calibers show Geneva stripes on the bridges, polished bevels, and a rotor with deep engraving. Fakes use stock ETA clones or Asian copies. Signs to check: printed rotor text, no perlage, coarse screws, and a regulator index of a generic shape.
Paperwork and price
A full set has a warranty card with the reference and serial, a booklet, and a box with a label that matches. Numbers that do not match across card, caseback, and movement point to a watch built from mixed parts or to a fake. A price far below dealer stock for the same reference is a signal. Ask for service records and the name of the watchmaker who did the last service.
Before you pay
- Get the case number and serial in writing.
- Send both to IWC for an archive check.
- Ask for caliper readings of case diameter and thickness.
- Ask for a 10x macro photo of the dial and the caseback engraving.
- Pay with a method that allows a chargeback.
- Have a watchmaker open the case on arrival.
If the seller refuses any of these steps, stop. A seller with a genuine watch has no reason to hide the numbers.