Short answer

A fake IW328099 is a replica of an IWC watch that carries that reference number. The reference is six digits after the IW prefix. IWC uses the 3280 block across several current models, so confirm the exact model on the IWC site or with an authorized dealer before you compare a watch to photos. Replicas of steel IWC models sell for $200 to $600. Genuine examples sell for several thousand dollars. The price gap is the first test. No seller moves a real IWC at replica money.

What the reference number tells you

The IW prefix is fixed. The six digits identify case, dial variant and bracelet or strap. A full reference can carry a suffix that marks the strap type. Sellers of replicas often quote the case reference and skip the suffix. Ask for the full string, then check it against the catalog entry. A reference that does not match the case shape in the photos is a warning sign.

Price and source

Genuine IWC steel watches sit in the four to five figure range at retail. A used example holds most of that value. An offer at 10 percent of retail is not a discount. Check closed sales on watch forums and auction results for the same reference. Compare the seller's history: a dealer with no prior watch sales and stock photos is a risk. Payment by bank transfer or crypto removes your chargeback route.

Case and finish

Look at the case flanks under a light at a low angle. Genuine IWC brushing runs in one direction with even grain. Replica brushing often crosses at the lug roots. Check the lug edges for a sharp burr. Check the gap between the lugs and the caseband. On a real watch the transition is clean and the polish line is crisp.

Dial, hands and printing

Print under a loupe. Genuine dial text sits sharp with clean serifs. Replica print shows ink spread, uneven baseline and thick strokes on small text. Applied numerals should sit flat with no glue visible at the base. Hand length matters: hour and minute hands should reach the correct index marks. A second hand that stutters instead of sweeping in steps points to a cheap quartz or a low-grade automatic.

Movement

Ask for a photo of the movement through the caseback, or a video of the rotor. IWC in-house calibers carry engraved bridges and a signed rotor. Replica movements are often stock Sellita, Miyota or Chinese clones with laser-etched plates. Etching looks flat and sits on top of the finish. Engraving cuts into the metal. Timing data helps: ask for a timegrapher printout with rate and amplitude.

Caseback and serial

Caseback engraving on a genuine watch cuts deep with sharp edges. Replica engraving is shallow and soft at the corners. Serial numbers should sit on the caseback and match the paperwork. A serial that appears on multiple listings online is a copied number. IWC can confirm a serial through an authorized service center.

Box, papers and warranty

A complete set includes the inner box, outer box, warranty card, manual and hang tag. Replica sets copy the card layout but miss details: wrong card stock, wrong font weight, no dealer stamp, or a card number that does not match the case. A watch sold with no papers is not proof of a fake, but it removes a check. Price the watch as a watch-only piece if the set is missing.

Weight and dimensions

Ask for a caliper reading and a weight in grams. Case diameter, thickness and lug width should match the published specs for the reference. Weight is harder to fake because a clone movement and a plated case weigh less than steel and an in-house caliber. A reading that is off by a millimeter or a few grams needs an explanation.

Water resistance

Replica cases often fail a pressure test at 3 bar. Gaskets are thin and the caseback thread is rough. A seller who cannot show a pressure test result is selling a watch you should keep away from water. Genuine IWC models carry a stated depth rating that a service center can verify.

Buying risk

Counterfeit watches are trademarked goods. U.S. Customs and Border Protection can seize them at import, and the buyer loses the money. Resale of a counterfeit is a separate legal problem. If a deal looks like replica pricing, treat it as a replica and decide with that fact in hand.