Short answer
Replica IW545126 is a seller label. It is not a reference in IWC's published catalog. IWC numbers its watches with the letters IW plus six digits. The 5451 block sits in the Portugieser line. A listing that carries IW545126 shows the seller copied the format. It does not prove the watch matches an IWC spec sheet.
How IWC reference numbers work
Every IWC reference starts with IW. Six digits follow. The first four digits mark the model family. The last two mark the variant, the dial color, or the case metal. Two watches with the same movement can carry different full numbers. Buyers who compare a listing to the brand catalog should match all six digits, not the first four.
What replica listings claim
Listings for IW545126 style watches repeat a small set of numbers. Expect claims like these:
- Case diameter 40 mm to 41 mm, stainless steel
- Sapphire crystal with coating on both faces
- Hand-wound movement, 28,800 vibrations per hour
- Power reserve of 8 days on some variants
- Water resistance to 30 m or 50 m
Treat each line as a claim. Photos in a listing show one watch. The watch that ships can be another. Ask for a photo of the case back and the movement before any payment.
How to check a genuine IWC
- Case back. IWC cuts the reference and the serial into the metal. The strokes sit below the surface. Printed text sits on top.
- Serial number. Modern IWC watches carry a seven digit serial. The number must match the paperwork.
- Movement. Geneva stripes, blued screws, and an engraved rotor appear on genuine calibers.
- Crown. The IWC logo sits on the crown. Check the relief and the alignment.
- Papers. IWC warranty cards carry the reference, the serial, and the date of sale.
- Service check. An IWC boutique or service center can confirm a serial against brand records.
Law in the United States
Import of a counterfeit watch into the US is barred under 19 U.S.C. 1526. CBP officers seize counterfeit goods at ports of entry and destroy them. Trafficking in counterfeit goods is a federal crime under 18 U.S.C. 2320, with up to 10 years in prison for a first offense. Trademark owners can sue under the Lanham Act, 15 U.S.C. 1114, for damages and fees.
One watch in a traveler's luggage can be seized and forfeited. A shipment of watches sold to buyers can bring criminal charges.
Bottom line
IW545126 is not a number IWC publishes. Buyers who want the Portugieser hand-wound look should confirm the full reference against the brand catalog, ask for the serial, and check the papers. A price far below retail is the first signal that a watch is not genuine.