Physical Address

304 North Cardinal St.
Dorchester Center, MA 02124

What is a COC (Certificate of Conformity)? Detailed Explanation and Requirements

In the automotive industry, the Certificate of Conformity (COC) is a vital document. It certifies that a vehicle meets all regulatory standards applicable at the time of its production. For automotive manufacturers, having a COC is essential to market their vehicles, especially in regions like the European Union (EU).

This guide will explain what a COC is, how it is obtained, and why it is crucial for automotive manufacturers.

What is a Certificate of Conformity (COC)?

A Certificate of Conformity (COC) is a document issued by the manufacturer certifying that a vehicle conforms to the approved type and complies with all regulatory acts in force at the time of its production. According to EU regulations, a COC ensures that the vehicle has undergone all necessary tests and meets the required standards. This certificate is mandatory for vehicles sold within the EU to verify that they meet safety, environmental, and performance standards​​.

Features of a COC

A COC must follow specific formats and include several security features to prevent forgery. These features can include the manufacturer’s registered watermark, ultraviolet fluorescent inks, temperature-sensitive inks, and other security printing features. These measures ensure the authenticity and integrity of the certificate​​.

Types of COCs

There are different types of COCs depending on the vehicle’s completion status:

  • Complete Vehicles: For fully assembled vehicles.
  • Incomplete Vehicles: For vehicles that are partially assembled.
  • Completed Vehicles: For vehicles that have been completed in multiple stages​​.
How to Obtain a COC

To obtain a COC, automotive manufacturers must go through a series of tests and inspections. These processes verify that the vehicle meets the relevant regulatory requirements. In the EU, manufacturers must apply to an approval authority and pass necessary tests to demonstrate compliance with safety, performance, and environmental standards​​.

Regulatory Framework: EU 2018/858 and EU 2020/683

The requirements for the COC are defined by the EU regulations 2018/858 and 2020/683. Regulation EU 2018/858 establishes the framework for the approval and market surveillance of motor vehicles and their trailers, and systems, components, and separate technical units intended for such vehicles.

It specifies that manufacturers must issue a COC for each vehicle produced, ensuring it complies with type-approval requirements.

Regulation EU 2020/683 further details the format and content of the COC, including the necessary security features to prevent forgery and the shift towards electronic COCs by 2026.

These regulations ensure that vehicles meet stringent safety and environmental standards before they are allowed on the market.

Paper Format of the COC

Traditionally, the COC is issued in paper format. This format details the vehicle’s main characteristics and technical performance in concrete terms. The certificate includes the manufacturing date and incorporates security elements to prevent forgery. The COC in paper format must be delivered free of charge to the buyer and should not depend on an explicit request or additional information​​.

Electronic COC

Starting July 5, 2026, manufacturers must provide the COC in electronic format. This change aims to make COCs more accessible and easier to manage. The electronic COC is given as structured data to the approval authority and follows secure data exchange protocols to ensure its authenticity and security​​.

Validity and Renewal of the COC

For ten years after the vehicle’s manufacturing date, manufacturers must provide a duplicate COC upon request. This duplicate must clearly indicate that it is a duplicate. This requirement helps ensure that older vehicles remain compliant with regulatory standards​​.

Benefits of the COC for Automotive Manufacturers

The COC offers numerous benefits to automotive manufacturers:

  • Legal Compliance: Demonstrates that the vehicle meets all regulatory requirements.
  • Market Access: Facilitates the import and export of vehicles, making it easier to enter global markets.
  • Consumer Confidence: Assures buyers that the vehicle is safe and meets high standards, boosting customer trust and satisfaction​​.

Why is a COC necessary?

A COC proves that vehicles meet regulatory standards and are safe. Without this certificate, vehicles cannot be sold in many regions, including the EU.

What tests are required to obtain a COC?

Manufacturers must pass various tests to prove that their vehicles meet safety, performance, and environmental standards set by approval authorities.

How long is a COC valid?

A COC is valid for ten years from the date of manufacture. During this period, manufacturers must provide a duplicate upon request.

What is an electronic COC?

An electronic COC is a digital version of the certificate that makes compliance documentation more accessible and easier to manage.


The Certificate of Conformity (COC) is essential for automotive manufacturers. It certifies that vehicles meet regulatory standards and are safe for sale. Available in both paper and electronic formats, the COC provides significant benefits, including legal compliance, smoother global trade, and increased consumer confidence. By obtaining a COC, manufacturers can ensure their vehicles are compliant and trustworthy, enhancing their market reputation and customer satisfaction.

Emre Cetin
Emre Cetin

I have been acquainted with homologation in the automotive sector for over 10 years now. We have accomplished great things in many projects within various teams. Adapting to the recently updated homologation processes has been particularly exciting. Integrating past experiences with new procedures fosters a fertile ground for innovation and productivity. Having a special interest and expertise in both automotive and technology,

I am thrilled by the prospect of these fields converging in the future. It is a privilege to be a part of the journey in automotive and technology!

For this reason, I have decided to launch a blog project that I have long envisioned, where I can share my experiences and assess developments in the industry.

Previously, in the early years of my career, I managed a well-loved project named, which offered content in Turkish. I had decided to discontinue this project for various reasons.

Now, I am excited to engage with an international audience through a new blog project, sharing knowledge and insights. I hope my efforts will contribute positively to the industry.

Please feel free to contact me with your views and suggestions.

Articles: 7

Leave a Reply