All About COSC Certification, Is It Important?

The Contrôle Officiel Swisse des Chronomètres (or the Official Swiss Chronometer Testing Institute) is an independent not-for-profit organisation that tests Swiss-made timepieces. The organisation is very specific about the standard of timepieces they will accept for testing, and even more particular about what would allow them to qualify for the COSC Certification. This ensures that any timepiece with the certification is of the highest quality materials and manufacturing. To be COSC Certified, a timepiece needs to be accurate to -4 to +6 seconds a day. It also needs to be Swiss-made and built from the highest quality materials with the greatest levels of care. 

The Origin of COSC Certification

The COSC was founded in 1973 in La Chaux-de-Fonds, Switzerland. Prior to this date, each Swiss watch canton tested their movements independently. This could not provide reliable information to the purchasers of these products as each canton’s testing standards were different. This meant that the results found in testing could not be compared to one another. This history emphasises the importance of the COSC as a neutral and reliable measure of the quality of a watch. 

Before the testing even begins, a timepiece submitted to the COSC must have certain qualities. The COSC will only certify Swiss-made movements. To be considered Swiss-made, a movement must have been assembled and tested by the manufacturer in Switzerland. At least 60% of production costs and 50% of the value of the components and assembly must be generated in Switzerland. This requirement made by the COSC means that timepieces built entirely outside of Switzerland cannot be submitted for COSC testing. This does not make them inferior but does mean that those movements with the COSC Certification are held to a very specific and traditional high Swiss watchmaking standard. 

Once the COSC has accepted a submission, they will test the movement for 14 to 20 days. Throughout this time, a movement will be placed in 5 different positions (3 o’clock, 6 o’clock, 9 o’clock, dial upwards and dial downwards) and at 3 temperatures (8˚, 23˚ and 38˚C). These changes will ensure that the COSC is able to gather accurate data on the timepiece to mimic it being worn by a purchaser. The COSC developed and tested all of their own equipment to make sure it is precisely designed for its purpose. They use custom tools, specialised premises, IT systems, atomic clocks and round-the-clock monitoring to ensure the accuracy of their testing. This means that if a timepiece is not deserving of the certification, it will not qualify. 

Is COSC Certification Important?

Having COSC certification gives the watch and its wearer a prestigious feel. By wearing a timepiece of this standard, a collector is exhibiting one of the finest examples of Swiss watchmaking. Each chronometer certified by the COSC has its own unique number engraved on the movement and a certificate issued by the organisation. The COSC are part of the Federation of the Swiss Watch Industry’s anti-counterfeit group, so prospective owners of these watches can be reassured of their authenticity. 

To maintain their status as a neutral and independent organisation, the COSC does not employ watchmakers. They are unable to advise and guide watch companies so they can simply observe and test with no bias. To further this, the organisation charges a consistent price per instrument tested. They do not offer discounts to returning brands or if a brand submits a large number of movements for testing. COSC make every effort to maintain a neutral, unbiased testing resource for Swiss watch companies. Any buyer of a COSC Certified chronograph can be certain that it is of the utmost quality.

The COSC is vital to Swiss watchmaking as it ensures a level of excellence is maintained within the industry. Only the most accurate and well-made timepieces receive the COSC Certification, meaning that only about 6% of all Swiss watches exported are certified. This makes owners of such a watch part of a very exclusive group. An especially inquisitive collector can contact the brand of their COSC Certified timepiece to request its test results. The availability of such precise knowledge adds a superior feel to COSC Certified chronographs making them the quintessential collector’s timepiece. 

COSC Certified Watches:

Certina DS-8 Chronometer Stainless Steel Bracelet Blue Dial C0334511104100

COSC Certification

A budget friendly option for a COSC Certified chronograph is this model from Certina. The stainless-steel bracelet is complemented by an eye-catching blue dial to create a modern, but classic, look. The high-quality materials of the case of the watch protect a Swiss quartz movement. The COSC certification of the model, along with its date aperture ensure optimal timekeeping.

The dial is protected by sapphire glass with an anti-glare treatment, increasing the watch’s readability in all conditions. A chronograph is a valuable addition to any collection due to the COSC’s reputation for only certifying the most accurate watches. This certified chronograph has simplicity and style, making it the perfect addition to a blossoming watch collection. 

Longines Record Men’s Swiss Automatic L28205117

Longines Watches

Launched as part of the Record Collection to celebrate Longines 185th anniversary, this watch combines vintage style with modern watchmaking excellence. This watch maximises the effect of the COSC certified chronometer by including an exhibition case back. This allows the wearer to fully appreciate and enjoy the expertise behind this incredibly accurate timepiece. The watch benefits from a silicon spiral, meaning that its accuracy cannot be compromised by magnetism or temperature.

The mixed metal stainless steel and 18 karat pink gold design of the watch makes it versatile and gives a touch of modernity. With an automatic movement of the calibre L888.4, this timepiece has a 64-hour power reserve. The COSC certification of this watch ensures it will be a long-lasting feature in any collection as to achieve such an accolade, the watch must be built by skilled watchmakers from the finest materials. 

ORIS Big Crown ProPilot Calibre 111 01 111 7711 4163-set 1 72 fc

COSC Certification

This luxury timepiece encapsulates what it means to be a certified chronograph. Only the highest quality materials have gone into creating a watch of this level of luxury and the certification guarantees that the movement will always be accurate. Inspired by aviation, the design is practical and attractive. The dial features two chronographs and large Arabic numbers, providing functionality and readability. A 10-day power reserve and power indicator sub dial mean the wearer never has to worry about their watch stopping.

This model features an exhibition case back to expose its COSC certified movement, allowing the wearer to take pleasure in both the reliability and appearance of such a high-quality movement. The dial is protected by sapphire crystal to ensure resistance to scratches, keeping the watch looking brand new for years to come. The brown genuine leather strap of this model makes it classic and comfortable and the screw-in crown ensures water resistance up to 10 bars. This watch is a perfect example of the exemplary Swiss watch making endorsed by the COSC, and the certification guarantees the quality and accuracy of the calibre 111 movement at the heart of this watch. 

Ball Watch Company Limited Edition Engineer II Rainbow COSC Automatic Chronometer 43mm Titanium NM2028C-L28CJ-BK

COSC Certification

This watch from Ball Watch Company will certainly stand out. The topstitched nubuck leather strap and rainbow indices make a departure from more traditional men’s watches. The hands and rainbow indices are luminescent to allow excellent readability in all lights. The 43mm case is made from titanium carbide to give the watch shock resistance up to 5000Gs.

Anti-glare treated sapphire glass protects the dial and a screw-in crown makes the watch water-resistant up to 100m. The timepiece is powered by an automatic movement of the calibre BALL RR1103-C and is COSC Certified, ensuring precise timekeeping. The eye-catching appearance and COSC Certification of this watch makes it the perfect accessory for the collector who loves to make a statement with an accurate and high-quality timepiece.  

Certina Men’s DS-8 Chronometer Watch C0334511603100

Certina Watches

At first glance, Certina’s DS-8 Chronometer looks like a classic men’s dress watch but hiding underneath the simple dial is a COSC Certified quartz movement. A movement of this standard guarantees that the watch has been made of high-quality materials by the most skilled hands.

This model is made more affordable because it is quartz powered, making certified chronographs accessible to more collectors. Sapphire glass protects the dial and date aperture of this model. The stainless-steel case and genuine black leather strap give the watch a classic and stylish feel and the COSC certification guarantees that the movement of the watch will be precise and reliable for years to come.  

Do you own a COSC Certified watch? If not, would you add one to your own collection? Let us know your thoughts in the comments below!

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