Short answer
IW371498 is not a reference number IWC publishes. IWC writes references as "IW" plus six digits. The first four digits name the family. 3714 is the Portugieser Chronograph. IWC catalogs list 371401 through 371491, and 371606 for the 2020 version. A listing that says IW371498 is a typo, a copied number, or a replica listing. Ask for a caseback photo before you send money.
How IWC builds a reference number
Four digits name the family and the movement block. Two digits name the metal, dial, and strap. So 371401 and 371446 share a case and movement but differ in dial and hands. A new movement or a new case size gets a new four digit block. That is why the 2020 Portugieser Chronograph became 371606 with calibre 69355.
The pattern holds across the catalog. 3777 is the Pilot's Chronograph. 5007 is the Portugieser Automatic. Numbers in the 3714xx block sit on watches sold from 2007 to 2020.
Numbers I could confirm
Public catalogs list 371401, 371404, 371417, 371438, 371445, 371446, 371447, 371491, and 371606. I could not find 371498 in any IWC price list, press release, or auction record. If a seller shows a card marked 371498, that card came from the seller.
Checks that separate a real 3714 from a fake
- Case: 40.9 mm across, about 12.3 mm thick, 30 m water resistance, 20 mm lug width.
- Dial layout: small seconds at 6, 30 minute counter at 12, date at 3. This layout is a strong filter, but some replicas copy it with a transfer plate.
- Movement: calibre 79350, 28,800 vph, 44 hour power reserve, 31 jewels. The 2020 ref 371606 uses calibre 69355 with a column wheel and 46 hours.
- Rotor: IWC engraves the rotor. Stamped text on a fake has rounded edges and a shallow cut.
- Hands: where the reference calls for blued hands, the blue comes from heat. Heat blue shifts with the light. Lacquered blue looks flat at every angle.
- Print: dial text sits on one baseline. On fakes the "Schaffhausen" line drifts up or down. The date numeral on a fake is wider than the IWC font.
- Crystal: the sapphire has coating on both faces, so the reflection is faint and takes a blue tint. Take photos at an angle, not straight on.
- Rotor wobble: a 7750 base moves on the wrist. Real and fake watches both do this. It is not a test.
Paperwork and price
Real watches ship with a warranty card. The card number matches the caseback number. Cards get copied, so ask for one photo that shows the caseback and the card in the same frame. Pre-owned steel 3714 listings cluster between $5,000 and $8,000. A $700 watch sold as a 371498 is a replica. No factory builds a correct 371498 because the number does not exist.
Verification steps
- Ask for the caseback photo, the serial, and the reference.
- Compare the number to the IWC catalog list.
- Send the watch to an IWC service center. The center reports parts that do not match.
- Keep the listing text and the photos. Pay with a method that has a refund window.
IWC does not issue letters of authenticity for private sales. A service invoice is the closest document you can get.