Quick answer
"45100" is not an Audemars Piguet reference number. No AP reference in the current catalog, and none in auction archives, uses that format. Audemars Piguet reference numbers carry five digits and start with 15, 16, 25, 26, 27, or 77. "Code 11.59" is not a code either. It is the name of a collection AP launched in January 2019. A watch sold with "11 45100" on the tag, box, or papers carries a number AP does not use.
How AP reference numbers work
A full AP reference looks like 26393ST.OO.A002CR.01. The first block is five digits and names the model family. The next two letters give the case material: ST for stainless steel, OR for pink gold, BA for yellow gold, BC for white gold, TI for titanium, CE for ceramic. The middle block describes the bracelet or strap. The last block is a dial and strap variant code. CR marks an alligator strap.
A bare number with no letter blocks is incomplete. That is the first thing to check on any listing.
What Code 11.59 means
Code 11.59 by Audemars Piguet launched at SIHH in Geneva in January 2019. The name refers to 11:59 pm, the minute before midnight. The case is round with an octagonal middle case, hollowed lugs, and a double-curved sapphire crystal.
Known references in the line include 15210 for the 41 mm selfwinding model, 26393 for the 41 mm chronograph, 77410 for the 38 mm selfwinding model, and 26395 for the Ultra-Complication Universelle RD#4. None of these is called "11.59" by itself. The phrase is a collection name, not a case code.
Where counterfeit numbers go wrong
- Invented five-digit numbers. 45100 does not appear in AP's catalog.
- Wrong digit count. AP uses five digits, not four or six.
- Missing material suffix. Real references carry letters and dots after the digits.
- Repeated movement numbers. AP stamps a unique movement number on each watch. Clones share numbers across units.
- Reference and movement numbers that do not match the model or the year.
- Case numbers and movement numbers that are identical. On most AP watches they differ.
How to check a number
- Read the reference from the caseback engraving, not from the hang tag or box.
- Compare the digits against an AP collection page or a recent auction lot.
- Find the movement number. It sits near the reference on the caseback or on the movement bridge.
- Send the numbers to Audemars Piguet. The company runs an authentication service from Le Brassus and charges a fee.
Legal note
Counterfeit watches are illegal to sell in the United States. US Customs and Border Protection seizes and destroys them at ports. Trademark holders can sue sellers and platforms that list them.