AP Chronicles Series EP.1 Decoding the numbers hidden in an AP watch serial number

Embark on a journey through the timepieces of a world-class classic brand like AP, or Audemars Piguet. We invite you to unlock the secret code of the serial numbers engraved in two positions on the watch cases, based on records from the brand’s legendary master craftsmen in Le Brassus. Follow the story of decoding numbers that serve as more than just identification, and trace the history of Audemars Piguet timepieces dating back to the 19th century in this article.

Tracing the Serial Number in AP watches

Audemars Piguet, or the AP watch brand, represents the beauty of timepieces designed for decades of use, with some models lasting for over a hundred years. Frequently, these timepieces are placed back on the workbench for repairs by other skilled craftsmen who possess specialized parts and experience—or even by professional collectors who risk opening the case back to perform repairs themselves!

Audemars Piguet has anticipated such possibilities ever since these timepieces left the production source to reach their true owners. For this reason, AP began assigning numbers to engrave a clear identity onto the cases, ensuring that if the manufacturer ever encounters the creations they crafted in the future, they can restore those modified models to their original condition accurately.

The path from case reference numbers to Serial Numbers

In the early days of AP watch history, the recorded numbers were created for internal use as a way to classify watches and identify repairs for the correct models. Although it is nearly impossible for outsiders to understand these code sequences, collectors and craftsmen alike have taken a keen interest, hypothesizing that these codes may bear witness to the history and origins of AP watches, including the parts and mechanisms designed for each model during that period. The registry for these pioneering Serial Numbers began in 1882 and continues to the present day, allowing those passionate about collecting pre-owned AP watches to immerse themselves in the evolution of rare, authentic timepieces!

Summary of the importance of Serial Numbers in AP watches

• Clearly indicates the year of production and the place of manufacture.
  Allows the manufacturer to track the watch throughout the production process.
  Verifies the authenticity of an AP watch, with details precisely specified through the numbers.

Movement Number: The first step in watch numbering development

The Movement Number, or the code sequence identifying an AP watch's mechanism, was first engraved in the 19th century. Each component has a specific number on the base plate or the bridge of the movement, and these numbers are stored in the production registry (Registre d'Établissage).

• Number 3824 corresponds to a dual-mechanism pocket watch sold in 1890, which has been verified as an AP watch from the Audemars Piguet Heritage Collection.
• Number 30674 corresponds to a watch with a Minute Repeater mechanism, polished gongs, and a bridge decorated with 29 Côtes de Genève patterns, sold in 1925 (Pre-Model 198 Audemars Piguet Heritage, inv. 1227).

Movement Numbers and production sequence

Starting with the Movement Number assigned by production sequence, watch historians have inferred that the total production of AP watches corresponds to the highest movement number at any given time. For example, watch number 30828 (1924) should theoretically be the 30,828th piece produced by Audemars Piguet, even though in reality, production in 1924 was limited and ended at 30,000 units.

However, from the second half of the 20th century onwards, assigning numbers based on movement became increasingly difficult and slowly faded away. With production numbers from the beginning approaching one million by 2020, the company redefined the mechanism numbering system by using two English letters followed by a four-digit sequence, starting from AA0001 up to AA9999 before resetting at AB0001.

Estimating the period when each Audemars Piguet model was first sold depends on the indicated movement number. Collectors interested in finding authentic pre-owned AP watches can use the table below to compare movement numbers and reference codes for assessment before making a purchase.

Differences in the Big Case Number

The Big Case Number emerged around 1951, separated from the movement serial number, to reflect case series that were produced and paired independently with AP watch mechanisms. The assigned numbers began with the case containing movement 54651, marked with the number 101, and subsequent numbers were assigned sequentially.

These numbers were later referred to as Case Registers. When the numbers approached 100,000, the company decided to update the numbering system once again to make it easier to engrave on the cases by combining English letters with numbers, starting with the letter B.

For example, an Openworked chronograph wristwatch produced in 1981 with the case engraving B61720, used in conjunction with a movement number indicating caliber 244108, would run until it ended at B99999, after which it would start with D1, marking a new series for easier identification of the production period and approximate product details on the case.

Inaccuracy of timeframes, the stepping stone to the Big Case Number

Even though AP watch movement numbers can be used to compare data and approximate production periods (as per the table provided earlier), this does not mean they are entirely accurate. Due to non-continuous data registration, gaps caused by mechanisms being stored for years before completion and sale, and multiple re-packagings in different forms, data complexity arose. For example, the Minute Repeater wristwatch number 8712, appearing on page 73 of the book *Audemars Piguet 20th Century Complicated Wristwatches*, was sold in 1951, but based on its caliber, it should belong to 1886.

This is why the Big Case Number system was created to overcome the limitations of identifying AP watches by Movement Number alone, while also indicating case series that were paired with movements independently. You can follow more interesting information about the stories behind the numbers on Audemars Piguet watches in the next article.

Looking for an authentic AP watch with a genuine serial number? Visit Pixiu Watch

After understanding the background of the Serial Number system, which holds many historical stories beneath Audemars Piguet timepieces, if any collector wishes to own an authentic pre-owned AP watch at a great price, don't forget Pixiu Watch. We are an experienced pre-owned designer watch store, and we have gathered these precious timepieces, waiting for you to discover their charm and take them home!

For further inquiries, contact us at 096-939-9292 (Oat) every day during business hours.

Reference

1. Audemars Piguet Heritage team. Le Brassus. AUDEMARS PIGUET WATCH NUMBERING. Retrieved December 23, 2022, from https://apchronicles.audemarspiguet.com/en/article/audemars-piguet-watch-numbering