Short answer
Almost every IW545128 advertised under $150 is a cheap automatic with an IWC logo glued onto the dial. A replica worth wearing costs $400 to $800, gets the dial print right, and uses a movement that at least resembles what IWC put in the real watch. Past $1,000 you are paying genuine-watch money for a counterfeit, which is the worst trade in this hobby.
If you are trying to work out whether a watch in a listing or on your own wrist is real IWC or a copy, the checks are the same ones a dealer runs: reference stamping, dial print, case finishing, and whatever is visible through the back.
What the reference number tells you
IWC reference numbers are not random. The 545x block sits inside the Portuguese family, so a watch stamped IW545128 should match that case shape, that dial layout, and that movement family. Replica sellers count on buyers who never look this up. Two minutes on the manufacturer's own reference page gives you the case diameter, the calibre, and the strap the watch shipped on. If the listing disagrees with the maker's own numbers, stop there and move on.
Where the fakes give themselves away
Dial and printing
Printing is the fastest tell. Genuine text sits crisp and slightly raised, with even spacing between the brand name and the place name underneath it. Cheap replicas print slightly fat letters, or thin ones that fade at the edges. On the subdial, check the ring: on a good watch the track is a clean circle with even hash marks, not a smudged printed ring. Applied indices should have polished bevels that catch light along one edge, not flat slabs. Hands matter too. Look at the tip shape and whether the finish runs all the way to the point or stops short.
Case, crown, and finish
A genuine case alternates brushed and polished surfaces with a hard line between them. On replicas that line wanders, and the brushed grain is coarser. Run a fingernail along the lug edges. Sharp, uneven burrs point to a low-tier case. The crown should have a crisp logo and no play when you wind it. Check the caseback engravings under a loupe: reference and serial numbers should be cut, not stamped flat, and the font should match the brand's own.
Movement
If the original is hand-wound, a rotor spinning behind the display back is an immediate fail. Beyond that, look at the decoration. Real finishing has stripes and perlage applied by hand or machine with consistent depth. Fake decoration is often a printed plate glued over a basic movement, and the giveaway is a flat, glossy surface with no depth under angled light. Ask for a clear movement photo before you buy.
Price tiers and what they buy
- Under $120: mineral glass, stamped caseback, printed decoration, wrong proportions. Fine as a costume piece, nothing more.
- $200 to $450: sapphire crystal and a decent case, but dial print and movement are still off. Most online listings sit here.
- $500 to $800: the bracket where the case finishing, dial, and movement actually hold up in hand. This is where a serious buyer should be looking.
- Over $1,000: no justification. You are near used-genuine territory for other references.
Checks before you pay
- Ask for dated photos of the actual watch, not factory renders that every seller reuses.
- Request a movement shot with the caseback off.
- Confirm the reference and serial engraving match between the caseback and the lugs.
- Ask what strap and buckle come with it, and whether the buckle logo is engraved or stamped.
- Accept that no replica comes with service support, so buy from someone with a return window.
Bottom line
The reference number on the dial is the easiest part to fake and the hardest part to verify, so use it as a starting point and not as proof. Judge the watch on the printing, the case lines, and the movement photo. A $600 replica of IW545128 that gets those three right will fool almost everyone at arm's length. A $120 one will not fool anyone who has held the real thing.