Short answer
"3399" is not an Audemars Piguet reference number. Audemars Piguet does not catalog any perpetual calendar watch as a 3399, and the number does not appear in the brand's Royal Oak, Code 11.59, or Jules Audemars materials. In practice, 3399 is a code used by counterfeit sellers and their agents to label one batch of fake perpetual calendar watches, typically a Royal Oak style case with a moonphase and four subdials. When you see "fake Audemars Piguet perpetual calendar 3399" in a listing or a forum thread, the number tells you which replica factory run the seller is talking about, not which real watch it copies.
Where the number comes from
Counterfeit sellers work from internal catalogs that list batches, not model references. They borrow four-digit strings because those strings look like reference numbers to a casual buyer. Buyers then repeat the code in searches, so it sticks as if it were official. A real Royal Oak perpetual calendar carries a five-digit reference such as 26574, 26394, or 25820, followed by a two-letter suffix that identifies the metal and dial, for example 26574ST.OO.1220ST.01.
What the 3399 listings usually show
- A Royal Oak style octagonal bezel with an integrated bracelet, often in steel or two-tone finish.
- A dial with four subdials plus a moonphase aperture, a layout that mimics the display of the AP caliber 5134.
- A caseback that copies the sapphire display back and rotor engraving but rarely matches the correct font or letter spacing.
- A movement that is either a modified Asian automatic or a quartz unit on the cheapest versions.
- A price between roughly 200 and 900 dollars, against a six-figure sum for a genuine perpetual calendar.
How to tell a fake perpetual calendar from the real thing
- Check the reference. Ask the seller for the full reference and compare it to the Audemars Piguet catalog. If the answer is 3399, it is not a real AP number.
- Inspect subdial spacing. On the genuine caliber 5134 the subdials sit in even gaps with no overlapping text. Fakes crowd the date and month windows together.
- Study the moonphase. Real AP moonphase discs are photographic and set into a recess. Fakes use printed foil that looks flat and reflective under a light.
- Weigh the case. A steel Royal Oak perpetual calendar feels dense because of the movement and finishing. Replicas feel light and hollow.
- Read the caseback engraving under magnification. Genuine AP engraving is sharp, deep, and even. Fakes show shallow laser marks and misspelled text.
- Test the winding feel. A genuine perpetual calendar winds with steady resistance and no grit. Cheap replica movements grind or spin free.
- Request paperwork. AP watches ship with documentation, and an authorized service center can confirm authenticity from the case and movement numbers.
The legal and practical side
Buying, importing, or reselling counterfeit watches is illegal in the United States. U.S. Customs and Border Protection can seize shipments and assess penalties, and trademark owners record their rights so that infringing goods are held at the border. Beyond the law, a fake carries no warranty, no service support, and no resale value. Audemars Piguet will not service a counterfeit, and many independent watchmakers turn them away because replacement parts do not exist. The metal content is also unverified, so a "steel" case may be plated brass that pits and flakes.
Options if you want the real complication
- Set a realistic budget. A genuine perpetual calendar from any high-end maker starts in the tens of thousands of dollars.
- Consider a real moonphase or full calendar watch from brands such as Frederique Constant, Baume & Mercier, or Longines if the look is what draws you.
- Buy pre-owned from a dealer with provenance, and have the watch inspected by an authorized service center before money changes hands.
- Verify every reference number against the maker's own catalog before you commit.