Buy the calibre and the paperwork first, then the dial. IWC builds several families that look similar at arm's length but behave very differently across ten years of ownership: an in house automatic with a long service interval and a registration warranty is a different asset from a discontinued model with an outsourced base movement and no history. Pin down four facts before you negotiate, the collection, the case material, the exact reference number, and the service record. Those four facts set the price far more than the strap, the box, or the dial colour.
What to look for on an IWC
- Reference and case material. The same design ships in steel, titanium, ceramic, and gold, and each version carries its own reference. Ask the seller for a macro photo of the caseback engraving and match it against the official catalogue entry for that collection.
- Calibre. Current in house families use a Pellaton style winding system and are labelled as manufacture calibres. Some older and entry level pieces use a modified outsourced base. The movement decides future service cost and parts availability.
- Service history. A stamped card or an invoice from a brand service centre is worth more than any accessory.
- Completeness. Original box, warranty card or digital certificate, manual, spare links, and spare straps. Incomplete sets trade lower and are harder to move later.
- Case condition. Light polish on a flank is normal. Rounded lugs and a softened bezel edge are not. Ask for close ups of the lug tips and the crown guards.
- Bracelet originality. Aftermarket end links and clasps are the most common substitution on the secondary market.
Parameter bands to compare
- Pilot's style pieces: about 40 to 43 mm, thicker cases, soft iron inner cage on some versions, 60 to 100 m water resistance, high contrast dials.
- Portugieser and dress lines: about 40 to 42 mm, slimmer profiles, 30 to 60 m water resistance, small seconds or chronograph layouts.
- Portofino and slim models: about 37 to 40 mm, the easiest fit on a smaller wrist, thinner lugs, quieter dials.
- Diver and sports models: about 42 to 44 mm, rotating bezel, 300 m water resistance, rubber or steel bracelet options.
- Power reserve: modern in house automatics run roughly 60 to 120 hours. Older outsourced bases sit near 40 hours.
- Wrist fit: lug to lug length matters more than diameter. Compare the published lug to lug figure against your own wrist measurement before you commit.
Pitfalls that cost money
Counterfeits exist in every popular IWC collection, and the tells sit in the details rather than the silhouette. Flat or slightly blurred dial printing, a date window with the wrong font or an off centre number, a rotor with coarse brushed finishing, and a shallow or uneven caseback engraving are all warning signs. A counterfeit also fails the simplest check of all: the reference will not line up with the calibre, the case material, and the production period when you verify it against official records.
- Frankenwatches: genuine case and dial, wrong movement or a bezel borrowed from another reference.
- Reprinted or refinished dials, which crush collector value even when the watch runs well.
- Aftermarket bracelets sold as original, often exposed by mismatched finishing on the clasp.
- Long gaps in service history, which mean an immediate cost after purchase.
- Pressure test claims with no paperwork, especially on dive models.
How to buy safely
- Verify the reference against the official catalogue page for the collection.
- Request a timestamped photo set: caseback, crown, clasp, dial macro, and movement where visible.
- Ask for the service history and the original purchase documentation.
- Use a payment method with buyer protection or a trusted escrow. Avoid bank transfers to strangers.
- Budget for a service and pressure test if the history is unclear.
- Have an independent watchmaker inspect the watch inside the return window.
FAQ
Do I need the box and papers?
For modern references, yes if you want to resell without friction. A complete set with card and bracelet sells faster and holds value better than a loose watch.
Is an in house calibre worth the premium?
Most of the time it is. Longer service intervals, better parts support from the brand, and stronger resale demand. The gap narrows only if you plan to keep the watch and service it locally.
Which size suits an average wrist?
On a US average wrist of about 6.7 inches, a 40 mm pilot's or Portugieser model with a lug to lug measurement under 50 mm wears comfortably. A 43 mm pilot's chronograph is a chunky watch on the same wrist.
How often does an IWC need servicing?
Most modern automatics run five to seven years between services in normal use. Dive watches need a pressure test more often, particularly after the caseback has been opened.
Can a dealer confirm authenticity?
A brand service centre can confirm whether the movement matches the case and reference. That is the most reliable check open to a private buyer.