Short answer
A fake Portofino moon phase is a copy of the IWC Portofino Automatic Moon Phase 37, reference family IW4594xx. IWC builds the real watch in Schaffhausen, Switzerland. Replica sellers list Portofino copies next to replica Rolex and Omega models in the same catalogs. In the United States, importing or selling one is illegal. Buying one abroad and carrying it home can end in seizure at the border.
The genuine reference
Facts to check against IWC's published product data:
- Case diameter: about 37 mm. Steel, red gold, or white gold, depending on reference.
- Movement: automatic, in-house caliber.
- Moon aperture: at 12 o'clock on the references in the IW4594xx range. The date sits inside the same aperture on some versions.
- Dial: Roman numerals and leaf hands on most versions.
- Strap: alligator leather on the original.
Confirm the hand layout and the aperture position for the model you are looking at. IWC has made more than one Portofino moon phase, and the layouts differ between them.
Where replicas diverge
A moon phase display runs off a toothed disc that advances one step per day. Tooth count sets accuracy. IWC publishes a drift figure for its moon phase calibers. Replica makers publish no figure, and no figure can be verified without a teardown.
Points that separate a genuine watch from a copy:
- Moon disc print: sharpness of the moon and stars, and whether the disc sits flush with the dial.
- Crystal: sapphire on the original. Many copies use mineral glass with a sapphire label.
- Caseback: engraving depth, font weight, and reference number placement.
- Movement: rotor finish, jewel count, and a real moon phase wheel instead of a 24-hour disc.
- Strap: alligator has visible scale structure and irregular edges. Embossed calf leather does not.
- Price: originals run in the thousands of US dollars. Copies run from about 50 to 400 US dollars.
A printed caseback and a box prove nothing. Counterfeiters copy packaging too.
US legal status
18 U.S.C. § 2320 makes trafficking in counterfeit goods a federal crime. A first offense carries up to 10 years in prison and a fine up to 2 million US dollars for an individual. Customs and Border Protection can seize and forfeit counterfeit imports under 19 U.S.C. § 1304 and related regulations. Watches are among the categories CBP reports in seizure data.
Repair is a second problem. IWC service centers will not touch a counterfeit, and no parts supply exists for replica movements.
What is not known
Replica production is not documented. Factory names, movement origins, and batch sizes circulate in seller listings and cannot be checked against a public record. Treat any claim about a specific factory as unverified.