Short answer: no single detail proves an IW323773 is fake. Confirm four points together: the caseback reference and serial pair, the engraving depth and font, the movement beat rate and finishing, and the crown and crystal fit. If two or more fail, treat the watch as a replica.

Tools for the check

  • 10x loupe or a clip-on macro lens for a phone
  • Digital calipers
  • Gram scale accurate to 0.1 g
  • Timegrapher, or access to a watchmaker who has one
  • Soft cloth and a glare-free work surface

1. Pair the reference and serial

  1. Turn the watch over and read the caseback text.
  2. Confirm the reference reads IW323773 with the digit spacing IWC uses.
  3. Note the serial number on the same caseback.
  4. Send both numbers to IWC service and ask for a match.

A genuine caseback carries one reference and one serial, cut at the same depth. Replica casebacks reuse a small pool of serials, so a web search that returns the same number on several forum listings is a red flag.

2. Read the engraving under magnification

  1. Set the loupe on the caseback lettering.
  2. Look at the inside edges of each cut.
  3. Compare font weight and spacing with photos of a documented genuine example.

Genuine engraving has a bright, clean edge and even depth across the full line. Fake engraving looks sandblasted, with rounded shoulders and letters that change depth along the word.

3. Inspect the dial and crystal

  1. Tilt the watch under a lamp and check the anti-reflective tint on the crystal.
  2. Inspect the dial print at 10x, mainly the brand line and minute track.
  3. Check the date window against the aperture edges.

Genuine dial print sits crisp with sharp serifs, and the date sits square in the window on a correct font. Replica dials show thick, merged lettering and a date wheel with a generic font that sits high or low in the cutout.

4. Test the crown and case finishing

  1. Unscrew the crown and count the turns until it seats.
  2. Check that the crown logo is deep and centered.
  3. Run a fingernail along the case flanks and lugs.

Genuine threading engages smooth and stops clean. Fakes feel gritty or spin past the stop. Genuine case flanks show even brushing with crisp edges; replicas show rounded edges and brushing that runs one way across every surface.

5. Verify the movement

  1. Put the watch on a timegrapher and read the beat rate.
  2. Confirm rate and amplitude sit in a sane range.
  3. Open the caseback with the correct tool and compare the rotor and bridges with IWC photos of the stated calibre.

Most current IWC automatics run at 28,800 vph. A 21,600 vph reading on a reference sold with a 4 Hz calibre points to a swapped or replica movement. Finishing counts as well: genuine bridges carry sharp Geneva stripes and properly polished screws.

6. Measure and weigh the watch

  1. Measure case diameter and thickness with calipers.
  2. Weigh the watch with the bracelet set to the same link count as the published spec.
  3. Write both numbers down next to the reference spec.

A 0.5 mm thickness gap or a 15 g weight gap is enough to justify a professional inspection before money changes hands.

7. Review the paperwork

  1. Check that the serial on the warranty card matches the caseback.
  2. Compare box printing and booklet paper stock with a known genuine set.
  3. Confirm the dealer name on the card is a real authorized retailer.

Replica kits ship with cards printed on the wrong stock and serials that do not match the watch. A card with no dealer stamp, or a stamp for a shop that does not exist, closes the case.

If the watch fails the checks

  1. Stop the payment and keep the listing screenshots.
  2. Ask IWC service for written confirmation of the serial result.
  3. Report the seller to the platform and to your national consumer authority.

Written confirmation from the brand is the document that wins a chargeback or a dispute. Photos alone rarely do.