Short answer
A fake IW321801 usually gives itself away within a minute of handling. Check the caseback engraving first, then the dial printing, then the crown and the movement. Genuine IWC engraving is cut deep, evenly spaced, and tied to a serial number the brand can trace. Fakes use shallow laser etching, wrong fonts, or a serial that does not match the reference. If any of those three checks fail, stop and walk away.
What a correct IW321801 should show
Before you inspect anything, pull the published specification for this reference from IWC or a reputable reference guide. Write down four items: case diameter, case material, movement caliber, and dial layout. Every later check is a comparison against that short list.
- Caseback stamping that carries both the reference and the serial number
- Applied markers with sharp edges and level lume fill
- A mechanical movement that matches the caliber listed for the reference
- A crown that screws down and carries the correct logo
- Bracelet or strap hardware in the finish the reference calls for
How to check the watch step by step
- Write down the reference and serial numbers from the caseback.
- Compare the reference format to IWC's own documentation for this model.
- Photograph the caseback engraving with a light held at a low angle.
- Inspect the depth and edges of that engraving with a 10x loupe.
- Check the dial text for spacing, font weight, and alignment at 12 and 6.
- Confirm the date window font, position, and cutout shape match the reference.
- Turn the crown and confirm it screws down on smooth, firm threads.
- Charge the lume and compare brightness and evenness across all markers.
- Weigh and measure the watch, then compare against the published specs.
- Have a watchmaker open the caseback and photograph the movement.
- Match the movement markings, rotor, and finishing to the caliber IWC lists.
- Ask the seller for the original invoice, warranty card, or service papers.
Red flags on most fakes
- Caseback numbers that do not match the reference in the listing
- Painted markers instead of applied metal markers
- Dial text that runs thick, thin, or off center
- Packaging with misspelled booklets or a plain white box
- A price far below the market range for the reference
- A seller who refuses a return window or an inspection period
- A quartz movement inside a reference that should be mechanical
Before you pay
Buy from a seller who allows an inspection period and a refund. Meet at a watchmaker's bench when you can, and finish the movement check before money changes hands. Keep the photos you take during the inspection. If the watch turns out to be counterfeit, those photos support a claim with your payment platform or a report to the brand. Note that importing or selling counterfeit branded watches is illegal in many countries, so a low price on a fake can cost more than the watch.