Quick answer
The reference number IW545113 does not prove a watch is genuine. Counterfeiters copy reference numbers straight from catalog photos, so a fake can carry the same engraving as a real IWC. You confirm authenticity by checking the caseback engraving, the dial print, the crown and pusher action, the movement, and the paperwork against a known genuine example of the same reference. If any one of those checks fails, treat the watch as counterfeit no matter what the seller claims.
What the reference number tells you
IWC reference numbers are internal model codes that point to a case, dial, and movement combination. They appear on the caseback, on the warranty card, and in service records. Because the number is published in listings and auction archives, it is one of the easiest details to duplicate. A matching number is a starting point for verification, not the finish line.
Prerequisites
- 10x jeweler loupe and a bright, diffused light
- Soft cloth and a quiet, dust-free surface
- Phone camera with macro mode
- Digital scale that reads to 0.1 g
- Reference photos of a genuine IW545113 from an authorized dealer or auction archive
- Access to a watchmaker who services IWC movements
How to check an IW545113
- Photograph the dial and caseback in flat light before you handle the watch, so you have a record of the condition and the engravings.
- Weigh the watch head and compare the result with the published specification for that reference. Counterfeits often miss the genuine weight by several grams.
- Study the caseback engraving through the loupe. Look at letter spacing, engraving depth, and the shape of each character. Genuine markings are cut deep with crisp edges. Copied markings look shallow and soft.
- Check the dial print at 10x. Text should be level, sharp, and free of ink bleed. Applied indices should sit flush with no glue visible at the base.
- Inspect the hands and date window. Look for uneven finishing, wrong hand length, and date magnification that does not match the genuine spec.
- Operate the crown and pushers. Winding should feel smooth, clicks should be defined, and the crown should seat with no wobble.
- Have a watchmaker open the caseback. Check the movement finish, rotor engraving, jewel count, and whether the calibre matches the reference. A generic clone movement under an IWC rotor is the clearest sign of a fake.
- Ask an IWC authorized service center to verify the reference and serial against the factory record before money changes hands.
- Compare the box, warranty card, and paperwork. Fonts, print quality, and serial matching all need to line up with the watch itself.
Red flags
- Price far below the market range for the reference
- Seller refuses to let a watchmaker open the case
- Photos that avoid the caseback or the movement
- Serial number that appears in other listings
- Box and papers that arrive after the sale, or not at all
If you already bought one
Stop wearing the watch. Photograph everything, keep the messages with the seller, and ask a watchmaker for a written opinion on authenticity. Use that document to open a dispute with your card issuer or payment platform. Report the sale to your national consumer protection agency and to the brand's anti-counterfeiting contact.
Legal note
Buying, importing, or reselling a counterfeit watch is illegal in the United States and most of Europe, and shipments can be seized at customs. A replica IW545113 is not a gray market watch. It is a counterfeit, and it carries the same legal exposure as any other fake good.