Quick Answer

A fake IW323718 usually fails on three points: the caseback engraving, the movement inside, and the price. If the reference number is stamped with shallow, uneven lettering, if the movement is a stock automatic with no IWC marking, or if the asking price sits far below the pre-owned market, treat the watch as a replica until a watchmaker proves otherwise.

What the Reference Number Covers

IWC assigns a reference number to one exact build: case material, case size, dial color, hands, strap, and movement. The number on the caseback, the card, and the box should all match. Most fakes reuse a popular reference number on the back while the rest of the watch copies a different model, so the dial layout is the first thing to compare against the reference.

Six Checks You Can Do in Five Minutes

  1. Turn the watch over and read the engraving. Genuine IWC caseback text is deep, sharp, and evenly spaced. Copies show soft, shallow marks with uneven spacing.
  2. Compare the dial text with photos of the reference. Font weight, print size, and the alignment of the logo and model line should match.
  3. Look at the date window. The aperture should have crisp corners, and the date should sit centered in the opening.
  4. Check the crown. It should turn with light resistance, screw down to a stop, and sit flush against the case.
  5. Inspect the lugs. Polished and brushed surfaces meet on a straight line, with no waviness along the edge.
  6. Weigh the watch in your hand. A steel IWC has real heft. A plated copy feels light for its size.

Checks That Need a Watchmaker

  1. Ask the seller for a movement photo with the caseback removed. Look for IWC engraving on the rotor and bridges.
  2. Compare the movement number with the reference number. Copies often hide a generic movement behind a decorated rotor.
  3. Have the rate measured on a timegrapher. Genuine movements hold a steady rate in several positions. Cheap copies drift.
  4. Test the crystal with a steel tool. Sapphire resists a scratch. Mineral glass takes one.

Paperwork, Serial Numbers, and Price

  1. Match the serial number on the caseback to the warranty card and the original receipt.
  2. Check the card date against the production period for that reference.
  3. Compare the asking price with recent sold listings for the same reference. A gap of 60 percent or more points to a replica.
  4. Ask for the service history in writing. A seller who cannot name a service center is a red flag.

What to Do With a Suspected Fake

  1. Stop the payment if it has not cleared.
  2. Photograph the caseback, dial, crown, and clasp in daylight.
  3. Send the photos to IWC customer service or a brand-approved service center for a written opinion.
  4. Report the listing on the platform where it appeared.

Why Photos Alone Are Not Enough

Modern copies photograph well. Phone processing, soft light, and careful angles hide machining marks, off-center date wheels, and thin plating. Any opinion based only on marketplace photos is a guess. The caseback removal and the timegrapher reading are the two steps that settle the question, and both require hands on the watch.

Before You Buy

Buy from a seller who accepts a return window long enough for an independent inspection. Pay with a method that offers buyer protection. A genuine reference at a fair price will survive that process. A replica will not.