Short Answer
A fake IW323733 is a copy of an IWC reference that carries the correct-looking number on the caseback but not the matching case, movement, dial, bracelet, or papers. Because counterfeiters stamp a reference number onto generic cases, the number by itself proves nothing. You confirm a genuine watch by matching the reference to the serial, measuring the case, reading the movement, and checking the original paperwork against the brand's own records.
What You Need
- A 10x loupe or a phone macro lens
- Digital calipers
- A timegrapher, or a timing app plus a quiet room
- Sharp photos of a known-genuine IW323733 for side-by-side comparison
- The seller's full documentation, including service history
How to Check an IW323733 Step by Step
- Look up the reference and serial pairing with IWC directly. Send the caseback number and serial to an authorized dealer or the brand's service center. If the two do not belong together, stop here.
- Examine the caseback engraving with the loupe. Genuine markings are cut clean and consistent, with even depth and correct letter spacing. Laser printing, shallow etching, or a font that drifts from the brand's official style is a warning sign.
- Measure the case with calipers. Compare diameter, thickness, and lug width against the published specs for the reference. Copies often run a millimeter or more off, and the case profile looks thick at the lugs.
- Study the finishing under a light. Look for sharp transitions between brushed and polished surfaces, crisp bevels, and a crown that seats flush. Rounded edges and sloppy polish are common on copies.
- Inspect the dial and hands. Check the printing under magnification, the alignment of every marker, and the color match of the luminous material. Center the hands at 12 and confirm they line up with the indices.
- Open the watch or view the movement through the caseback. Genuine IWC movements carry correct engraving, perlage, and signed rotors. Generic movements with rough finishing, plastic movement rings, or missing decoration do not match the reference.
- Run it on a timegrapher. Note the rate, amplitude, and beat error. Consistent numbers within the movement's rated tolerance are a good sign. Wild rate swings or a weak amplitude point to a low-grade movement.
- Check the bracelet, clasp, and spring bars. Look at the end-link fit, the clasp engraving, and the screws. Copies often show gaps at the lugs, loose pins, or stamped clasps that feel light.
- Compare the price to live market listings for the same reference in the same condition. A price far below the market range on a complete watch is the most reliable single red flag.
- Buy or sell only after an independent authentication. A watchmaker who works with the brand, or the brand's own service center, can confirm the movement and case in person.
Paperwork and Seller Behavior
Genuine boxes, booklets, and warranty cards are printed correctly and match the reference. Check that the card serial matches the case serial and the movement number. Sellers who refuse to open the caseback, who will not provide the serial in writing, or who push for a fast bank transfer outside a protected payment method are telling you what the watch is.
If a watch fails two or more of the checks above, treat it as a fake IW323733 and walk away. If it passes all of them, still confirm the movement and serial pairing with the brand before money changes hands.