Short answer

A fake IW328092 almost always fails on the caseback engraving, the dial print, the movement, or the paperwork. Check those four in that order. Genuine IWC engraving is even in depth and sharp at the edges; replica engraving looks soft, shallow and slightly wide. If the caseback is wrong, stop there and do not pay.

What you need

  • A 10x loupe or a phone with a macro lens
  • Digital calipers
  • A small digital scale
  • Bright, diffused light
  • The IWC product page for the reference open on your phone

Step 1: Confirm what the reference should be

Pull the official IWC page for the exact reference before you touch the watch. Note the case diameter, the calibre number, the crystal type, the dial variant and the strap or bracelet option. Replica sellers mix parts from different variants, so a watch that is right in one detail is often wrong in three others.

Step 2: Check the case and finishing

  1. Measure the case diameter with calipers and compare it with the published figure. Replicas commonly run 0.3 to 0.8 mm oversize.
  2. Weigh the watch head. A plated brass replica feels light for its size next to a steel case.
  3. Run a fingernail along the lug edges and the case flank. Genuine edges carry an even chamfer with no burr.
  4. Inspect the crown logo under the loupe. The strokes should be square-cut and centered, not rounded and off-center.

Step 3: Read the dial under magnification

  1. Look at the printed text. Genuine print is solid, with no ink pooling or bridging between letters.
  2. Check the applied numerals and indices for height and alignment against the minute track.
  3. Examine the date aperture. The disc should sit flush and the font should match reference photos.
  4. Charge the lume with a phone light for 20 seconds. Poor replica lume glows patchy and dies in minutes.

Step 4: Inspect the movement

  1. Look through the display back at the rotor and bridge engraving. Text should be laser-sharp, not soft-edged.
  2. Check the beat rate with a timegrapher. It must match the calibre listed on the IWC page for that reference.
  3. Wind and set the watch. The crown should feel firm with no grinding, and the date should flip cleanly at midnight.

Step 5: Verify the caseback and serial

  1. Read the reference number engraved between the lugs. It must read IW328092, not a neighboring reference.
  2. Check the serial number format and confirm it matches the warranty card.
  3. Look for tool marks around the caseback seam or screws. Factory assembly leaves none.

Step 6: Check the paperwork

  1. Match the warranty card serial to the case serial, digit for digit.
  2. Inspect the print quality on the card, the booklet and the box insert.
  3. Ask for the original sales receipt with an authorized dealer name on it.

Red flags that end the deal

  • Seller refuses a movement photo or a caseback close-up
  • Serial on the card does not match the case
  • Price far below the current secondhand market for the reference
  • Watch ships from a different country than the seller claims
  • Pressure to pay by bank transfer or crypto only

When in doubt

Have an independent watchmaker open the case and confirm the calibre before money changes hands. A ten-minute inspection costs less than one bad purchase, and a genuine seller will not object to it.