The best of watchmaking at Watches & Wonders from April 1 to 7
The world's largest annual watchmaking trade show opens its doors again from April 1 to 7, 2025.
Our organization
An association that rises to the challenge
Our hybrid organization is composed of public authorities and watch brands, committed to preserving, promoting and certifying Swiss watchmaking excellence.
Balance, neutrality and transparency
The COSC is a public-interest association dedicated to promoting Swiss watchmaking. The Board of Directors, composed of representatives from public authorities and watch brands, reflects our founding mission: to bring together the key industry players within a neutral, independent institution that is universally recognized for certifying the precision of Swiss watch movements.
Our governance
The General Assembly
It is the supreme decision-making body of the COSC, and its composition reflects the desire for balance among the various players.
It consists of:
Ten delegates from public authorities (cantons, managing authorities, and the Federal Institute of Metrology METAS).
Nine delegates from the private sector, proposed by the Federation of the Swiss Watch Industry.
The Board of Directors
Elected by the General Assembly, it plays a central role in the governance of COSC and consists of 8 members: the Chairman, the Vice-Chairman, three delegates from the public authorities representing the three laboratories, and three delegates representing all COSC client brands.
The Management Team, located in La Chaux-de-Fond
It is responsible for workflow processes, equipment, quality, relations with watchmaking brands and public authorities, as well as those of administration and accreditation.
As Time goes by
The certification
FAQ
What does the COSC represent for a watch?
The COSC is a guarantor of high precision and quality for a watch. When a watch is certified by the COSC, it receives the official designation of “chronometer,” meaning that it has passed a series of rigorous tests to verify its precision. These tests are based on strict criteria defined by the ISO 3159 standard for mechanical watches, and internal requirements for quartz watches. The COSC certification is a guarantor of expertise and reliability, enabling manufacturers to stand out in the market by offering added value to their products.
What is the COSC certification?
The ISO 3159 standard is an international reference that governs methods for testing and evaluating the precision of chronometers. It seeks to establish uniform criteria for the testing and evaluation of timekeeping devices, whether they be watches, clocks or other chronometric instruments used in specific applications such as sports competitions, scientific instruments or military equipment. The ISO 3159 standard plays a key role in standardizing the methods used to ensure the precision, reliability and durability of chronometers.
Guarantor of precision: Users can have the assurance that chronometers tested in accordance with the ISO 3159 standard meet strict precision criteria, and that the results of the time measured are reliable.
Interchangeability: The uniform application of this standard throughout the world makes it possible for time measurement instruments to adapt to international measurement systems, offering greater flexibility for users.
Performance optimization: By establishing clear criteria for chronometer performance, the standard encourages manufacturers to constantly improve the quality of their products.
Certification and international recognition: Those chronometers that meet the requirements of ISO 3159 can be certified, enabling manufacturers to gain an international recognition for the precision and reliability of their products.
The ISO 3159 standard represents a major step forward in the management of chronometer accuracy and performance. By providing a framework for rigorous, standardized testing, it ensures that these instruments meet strict reliability criteria, which is essential in fields where time is critically measured. By ensuring greater reliability, this standard strengthens the confidence of users - whether industry professionals, top sportsmen and women, researchers or consumers - in the accuracy of the chronometers they use.