The search term fake IW328020 points to one of two situations: a replica listed as an IWC with that reference number, or a genuine watch whose photos and paperwork do not match the reference on the case. You cannot settle the question by looking at listing photos. You settle it by comparing the physical watch against the manufacturer's published specification for that exact reference. Reference string, case diameter, case thickness, movement calibre, beat rate, power reserve, dial layout, and bracelet part codes all have to line up. When one item misses, the watch is a replica or a genuine watch carrying swapped parts.
Before you start
- Digital calipers that read to 0.1 mm.
- A 10x loupe or a phone macro lens.
- The maker's official catalog entry for the reference, plus archived spec sheets for older production runs.
- A kitchen scale that reads in grams.
- The seller's photos, the full serial number, and any service record.
How to check an IW328020 for authenticity
- Look the reference number up in the brand's current catalog and in discontinued model archives. If the number does not map to a documented model with published specs, stop there and treat the listing as suspect.
- Measure the case diameter across the 3 and 9 o'clock line with the calipers. Replica cases usually run wider or narrower than the factory figure by several tenths of a millimeter.
- Measure the case thickness from the crystal top to the caseback center. Replicas run thick because the clone movement and spacer take more room than the original calibre.
- Weigh the watch head without the strap or bracelet. A head that comes in well under the expected figure points to a hollow case or a lighter alloy.
- Examine the dial print under the loupe. Compare stroke weight, letter spacing, and the position of the brand mark against a verified photo of the same reference.
- Check the lume plots and hands at the same magnification. Uneven application, off-center plots, or a mismatched hand length are common on replicas.
- Study the date window and any cyclops. Look at window edge finish, date font, and how the numerals sit in the aperture.
- Inspect the crown engraving, thread pitch, and winding action. A gritty or loose crown with shallow engraving is a warning sign.
- Read the caseback engraving with the loupe. Compare the font, depth, and spacing of the reference and serial numbers against genuine examples of the same production year.
- Check the movement behavior. Time the beat rate against a timegrapher app and compare the amplitude and rate to the calibre stated for the reference.
- Open the caseback if the design allows it, then compare rotor engraving, bridge finishing, and jewel count to the factory calibre.
- Test the bracelet or strap fit. Measure the gap at the lugs and the endlink play. Genuine parts seat with no visible gap.
- Examine the clasp engraving and screws. Look at the stamping depth and whether the screw heads are the correct type.
- Match the serial number on the caseback to the warranty card and any box label. Numbers that do not match across all three are a hard stop.
- Have a watchmaker pressure test the case if the seller claims water resistance. Do not accept the claim without a test.
- Compare the asking price to the current secondary market range for that reference in that condition. A price far below the range signals a replica or a stolen watch.
Red flags that confirm a replica
- A reference number that does not appear in the brand's catalog or archives.
- Case dimensions that miss the published figures by more than 0.2 mm.
- Dial text with the wrong font weight or the wrong spacing between letters.
- A movement beat rate that does not match the calibre specified for the reference.
- A serial number that repeats across several listings from different sellers.
- Photos that are stock images rather than shots of the actual watch.
If you already own a suspected fake
- Stop any payment still in progress and request a chargeback from your card issuer or payment platform.
- File a counterfeit report with the platform where the listing appeared.
- Report the import to U.S. Customs and Border Protection if the watch entered the country as a genuine item.
- Keep the listing screenshots, messages, and receipt together for the claim.
What buyers get wrong
Most buyers judge a watch by the dial photo. That is the one part of a replica that makers copy with the most care. The parts that expose a copy sit out of frame: case thickness, movement beat rate, caseback font, and serial consistency. Work from calipers and a timegrapher before you work from pictures. A watch that passes the measurements and fails the paperwork is still a problem, and a watch that passes both is worth a professional inspection before money changes hands.