Short answer
11 45100 is not an Audemars Piguet reference number. It belongs to the shorthand that circulates in replica listings and buyer chat threads, where sellers tag a factory batch or a case and dial combination with a short numeric string. Genuine AP references are longer, mixed letter and digit runs, and the brand does not publish anything in that five digit pair format. When a listing leads with a code like this and never shows a full reference, treat it as a batch label rather than a model identity.
How real Audemars Piguet references are built
AP writes references as a chain of codes. Take a Royal Oak 16202ST.OO.1240ST.01. The first block identifies the model family and case size. The next block carries the metal, so ST for stainless steel, OR for rose gold, BA for yellow gold, TI for titanium. Then comes the dial code and, on bracelet models, the bracelet code. Two watches with the same model number can sit thousands of dollars apart because of the metal and dial blocks alone.
That structure is why a bare number like 11 45100 cannot describe a watch. It has no metal, no dial, no bracelet, no generation. It is a label someone typed, nothing more.
Where short codes like 11 45100 come from
- Factory or batch tags used by replica sellers to separate production runs.
- Chat group shorthand that gets copied between listings and forums without a source.
- Internal order numbers from a middleman's spreadsheet, not from AP.
- Typed movement or case numbers lifted from a photo and reused out of context.
None of these are stable. A batch tag that means one thing this season gets recycled for a different case next season, which makes the code useless as a buying signal even inside that market.
Why a code tells you nothing about the watch
Sellers lean on codes because they sound technical. A number implies a specification, a version, a known quantity. In practice, the same tag gets stapled to watches with different movements, different cases, different dial printing, and wildly different finishing. Buyers who compare notes in forums regularly find two watches sold under one code that share almost no parts.
The ranking that matters to collectors is factory reputation and revision history, and that information lives in photos, movement shots, and long term owner reports. It does not live in a five digit string.
What to check on a watch instead
- Full reference stamped or engraved correctly, in the right format for that model.
- Case and movement numbers that match between the watch and its paperwork.
- Movement finishing, engraved bridges, and rotor decoration that hold up under magnification.
- Dial detail: applied markers, correct date font, aligned subdials, clean printing.
- Documentation trail from an authorized dealer or a reputable reseller.
The legal and practical side
Counterfeit watches are illegal to import and sell in the United States, and customs agencies seize shipments on a routine basis. Beyond the legal exposure, a replica has no manufacturer service path, no parts support, and no resale market you can rely on. A watch that cannot be serviced by the brand that designed the movement is a paperweight with a bracelet.
Bottom line
Search 11 45100 and you will land on replica listings, not an Audemars Piguet catalog entry. If you want to identify or verify an AP, work from the full reference format, the movement, and the paperwork. If a seller cannot give you a complete reference and a matching history, the short code is doing the work of hiding that gap.