Short answer
A fake IW323705 is a replica of an IWC reference whose base number is IW3237, with the final two digits marking one dial and finish inside that family. On a replica, the giveaway is rarely the logo. It is the case profile, the bracelet integration, the dial furniture and the movement. Nail all four and the watch holds up in the hand. Miss one and it never does.
What the reference number tells you
IWC writes its references as a prefix plus six digits: IW323705. The first four digits define the case family, movement layout and overall proportions. The last two point to a variant. Two watches sharing the base number can differ only in dial color or finishing, which is exactly where replica makers cut corners. They photograph one variant and ship another.
So the first check happens before anything ships. Put the seller's photos next to the official spec sheet for that base reference. If the case diameter, lug geometry or bracelet link shape does not line up, stop there. No movement upgrade rescues a case built from the wrong drawing.
The four things that decide quality
1. Case profile and thickness
Measure it yourself with calipers when it lands. A genuine case spec is a fixed number, and replicas routinely run a half millimeter thick because the movement inside is taller than the original. That extra height shows up in the wrist presence and in how the watch sits under a cuff. Check the caseback engraving depth too. Laser etching looks flat and gray next to stamped or engraved text.
2. Bracelet integration
This is the hardest part to fake well and the easiest to check. Run a fingernail along the seam where the first link meets the case. On a good bracelet the gap is even and tight on both sides. On a rushed one it opens on one side and pinches on the other. Fold the clasp closed and listen. A crisp, single click is a good sign. Rattles and side play are not.
3. Dial furniture and printing
Applied markers should sit level and cast a real shadow. Printed text should be sharp under a loupe, with consistent stroke weight and no bleed into the dial finish. Check the date wheel alignment at several dates, not just the one in the photo. Font mismatches on the date disc are one of the most common replica flaws and one of the easiest to spot in daylight.
4. Movement and timekeeping
Ask what movement is inside and whether it has been regulated. Then verify. Wind it, set it, and watch the seconds hand sweep. Run it for 48 hours against a phone clock and note the daily rate. Anything drifting past roughly ten seconds a day needs a service, which is a real cost. Ask whether the date changes cleanly at midnight or creeps for two hours.
Questions worth asking before you pay
- Which exact variant is in stock, and can you send current photos of that unit?
- What movement is inside, and is it regulated before shipping?
- What is the return window, and does it cover a movement fault?
- Is the bracelet sized to my wrist, or do I need spare links?
- Do you have a photo of the caseback and clasp engraving up close?
Where replicas age badly
Water resistance is the big one. A screw-down crown and caseback gaskets are cheap parts, and plenty of replica cases are rated for splashes only, no matter what the listing says. Keep it away from pools and showers unless you have had it pressure tested yourself. Plating on two-tone pieces wears through at the clasp and crown first. Crystal coatings scratch and cloud. Buy knowing that a replica is a watch you enjoy for a few years, not an heirloom, and price it that way.
If the seller cannot answer basic questions about the base reference, the variant, or the movement, that tells you more than any photo will.