In this article, we examine the fundamental differences between a declaration of conformity and a certificate, explain when each is needed, and provide a comparison table for quick reference.
Declaration of conformity: essence and mechanism
A declaration of conformity is a document drawn up by the manufacturer or its authorized representative. By signing the declaration, the manufacturer assumes full responsibility for ensuring that the product complies with the requirements of the applicable technical regulations. No external body issues or approves this document—it is a statement made by the manufacturer itself.
This does not mean that the declaration is made “out of thin air.” It is always based on laboratory test reports conducted by an accredited laboratory and technical documentation confirming compliance with requirements. The manufacturer is required to store these materials and provide them to regulatory authorities upon request.
The procedure for issuing a declaration of conformity involves determining the applicable technical regulations, conducting tests in accordance with harmonized standards, compiling a technical file, and having the declaration signed by the head of the enterprise. The manufacturer bears full responsibility for the accuracy of the information provided.
Certificate of conformity: when a third party is needed
The certificate of conformity is issued by a conformity assessment body — an independent organization accredited by the NAAS. The body conducts its own assessment: it checks documentation, analyzes test reports, and in some cases conducts production audits. Only after a positive conclusion is a certificate issued.
The key difference is the distribution of responsibility. The manufacturer is responsible for product safety, while the authority is responsible for the accuracy of the assessment. If the product is found to be dangerous but the authority made a mistake in its assessment, it is also liable. For consumers and trading partners, the certificate is often perceived as a “more authoritative” document, although legally both have the same force.
The procedure for certifying products through a certification body takes longer and costs more, but for certain categories of goods it is the only legal way to confirm compliance.
| Criterion | Declaration of conformity | Certificate of Conformity |
| Who compiles/publishes | Manufacturer or importer independently | Conformity assessment body (third party) |
| Responsibility | Entirely on the manufacturer/importer | Distributed between the manufacturer and the authority |
| Validity period | Determined by the manufacturer (usually up to 5 years) | Determined by the authority (usually 1–5 years) |
| Cost | Lower (testing only) | Highest (testing + authority services) |
| Third-party involvement | Not mandatory (except for certain categories) | Mandatory |
| Legal force | Equivalent provided that the procedure is followed | Equivalent |
The main thing to understand is that manufacturers do not choose between declarations and certificates at their own discretion. The choice of procedure is determined by the technical regulations that apply to the products. Each regulation contains a list of conformity assessment modules and clearly indicates which ones are applicable to specific categories.
For most industrial products with low and medium risk levels, Module A is provided for—internal production control, which is completed by drawing up a declaration. For high-risk products or complex technical products, the regulations require the involvement of an assessment body—Modules B, C, D, E, F, G, or H in various combinations.
Examples for different product categories
Household appliances. For most household electrical appliances—kettles, irons, toasters—a declaration of conformity based on the results of electrical safety and electromagnetic compatibility tests is sufficient. Certification of household appliances through an assessment body is only required for certain categories with increased safety requirements, such as gas appliances or equipment operating under pressure.
Electrical products. Cables, circuit breakers, sockets, switchboard equipment — for these categories, the choice between a declaration and a certificate depends on the voltage, power, and purpose of the product. Certification of electrical products with the participation of a certification body is mandatory for products that directly affect human safety: power cables for stationary electrical wiring, protective devices, equipment for explosive environments.
Building materials. A separate system applies here: the manufacturer draws up a declaration of performance, but for many categories, the participation of a notified body in the verification of the factory production control system is mandatory. The certification of construction products provides for several assessment systems (from 1+ to 4), and it is the system that determines how deeply the assessment body is involved in the procedure.
Products for export to the EU. To enter the European market, the manufacturer completes an EU Declaration of Conformity and affixes the CE marking. Depending on the directive and risk category, the procedure may be either self-declaration (module A) or require the involvement of a European Notified Body. For medium- and high-risk products, the involvement of a Notified Body is mandatory.
Common mistakes when choosing a procedure
The first mistake is filling out a declaration for products that require certification. Such a declaration has no legal force, and during an inspection, the inspector will note the absence of the proper document with all the ensuing consequences: orders, fines, and removal of products from circulation.
The second is ordering a certificate when a declaration is sufficient. This is not a violation, but a waste of budget and time. The manufacturer pays for the services of the assessment body, although it could have made do with only the protocols of an accredited laboratory and a self-compiled declaration of conformity.
The third is the issuance of a “voluntary certificate” instead of the mandatory procedure. Voluntary certification does not replace the mandatory conformity assessment under technical regulations. These are two different legal instruments, and the existence of a voluntary certificate does not exempt a company from the obligation to issue a declaration or undergo mandatory product certification.
How to determine the right procedure for your products
The algorithm is simple: determine which technical regulations apply to your products, find the section on conformity assessment procedures in the regulations, and see which modules are provided for your category. If module A is provided, a declaration is sufficient. If modules involving a body are specified, a certificate is required.
The complexity lies in the fact that a single product may be subject to several regulations at the same time, and different procedures may apply to each of them. For example, industrial equipment may be subject to the Machinery Directive (requiring CE certification with the involvement of a notified body for dangerous machinery) and the Electromagnetic Compatibility Directive (where a declaration is sufficient).
Standards and Quality helps manufacturers and importers determine the correct procedure for each product category, prepare a complete set of documents, and undergo conformity assessment without unnecessary costs. We work with the entire spectrum — from issuing declarations of conformity for low-risk products to supporting full product certification through notified bodies for complex technical products. Contact us for a consultation, and we will help you choose the best path that complies with the law and fits your budget.
