Declaration of Conformity vs Certificate of Conformance
How a Declaration of Conformity and a Certificate of Conformance differ (regulatory self-declaration versus contractual supplier statement) and when a product needs one, the other, or both.
A Declaration of Conformity (DoC) and a Certificate of Conformance (CoC) sound almost identical, and both assert that something conforms, but they answer to different masters. A DoC declares conformity to regulation; a CoC certifies conformance to a contract. Confusing the two leads to sending a customer a regulatory declaration when they wanted a shipment certificate, or vice versa. This guide sets them side by side.
The core difference
An EU Declaration of Conformity is a manufacturer’s self-declaration that a product meets the applicable legislation: the legal document that underpins the CE mark, drawn up to a defined model. A Certificate of Conformance is a supplier’s statement that a specific shipment or lot meets the agreed requirements of a purchase order, drawing, or specification. One is a regulatory obligation to the market; the other is a contractual assurance to a customer.
| Aspect | Declaration of Conformity | Certificate of Conformance |
|---|---|---|
| Conforms to | Applicable legislation / directives | Contract, PO, drawing or specification |
| Issued by | The manufacturer (self-declaration) | The supplier for a shipment or lot |
| Driven by | A regulatory obligation | A customer or contractual requirement |
| Typical output | Underpins CE marking | Accompanies a shipment |
| Scope | The product model / type | The specific lot or delivery |
A single product can need both: a Declaration of Conformity to place it on the market legally, and a Certificate of Conformance with each shipment to satisfy a customer’s quality agreement.
When you need which
If the requirement is to place a product on the EU market, you need a Declaration of Conformity and, where applicable, the RoHS declaration that feeds into it. If a customer’s purchase order or quality agreement asks for documented assurance with a shipment, you need a Certificate of Conformance. Many manufacturers maintain both: the DoC as a standing, product-level regulatory document, and a CoC issued per shipment. Because both are controlled documents that must stay aligned with the product and its requirements, they benefit from fixed, version-controlled templates. DataSheets Pro gives you structured starting points for each; confirming the correct legislation, requirements and format remains your responsibility.
Start from the templateDeclaration of Conformity template: free & editable
Lay out the product, the legislation and standards it conforms to, and the responsible-party declaration, then export a print-ready PDF, free to start.
Open the template →Standardize this in DataSheets Pro
Turn what you just read into a repeatable, on-brand template, with no design tools required.