CE marking technical file: what goes in it

CE marking is a self-declaration, which means nobody checks your work before you ship — but if a market surveillance authority, a customs official, or a large B2B customer's compliance team ever asks, the technical file is what you hand over to prove the mark was earned, not just printed on the box. Building it after the fact, from memory, is where most CE headaches come from; building it as you go is far cheaper.

What the file actually needs to contain

There's no single universal template — the exact contents depend on which directives apply to your product — but a technical file assembled for a typical connected hardware product generally covers:

• A general description of the product and its intended use, including reasonably foreseeable misuse.
• Design and manufacturing drawings or diagrams, plus a list of the harmonised standards applied (or, where you didn't apply a standard fully, a description of the solutions used to meet the relevant essential requirements instead).
• Risk assessment records for every applicable directive — electrical safety, EMC, radio spectrum, RoHS, and any others your product triggers.
• Test reports from an accredited lab (or your own documented in-house testing, where the applicable directive permits self-testing).
• The Declaration of Conformity itself, signed and dated.
• Details of the manufacturer and, for non-EU manufacturers, the EU-based authorised representative or responsible person named on the product.

How long you have to keep it

Retention periods vary slightly by directive, but ten years from the date the last unit of that product was placed on the market is the figure that covers the large majority of common CE-relevant legislation for hardware — treat it as your default unless you've confirmed a specific directive requires longer.

What triggers a request to see it

A market surveillance authority can ask for the file at any time, with no complaint required to prompt it — spot checks happen. In practice, the more common trigger for a startup is a large B2B customer or a marketplace's compliance-review process asking for evidence before onboarding you as a supplier, which is often the first time founders realise their "we're CE marked" claim has no paperwork behind it.

Building it incrementally

• Start the file the day you finalise a design revision, not the day you ship — retrofitting test evidence for a product that's already shipped is far more expensive than commissioning it alongside development.
• Keep supplier declarations (for RoHS and REACH substance compliance) filed against the specific component revision they cover — a supplier's next revision may not carry the same declaration.
• Store the file somewhere durable and accessible for the full retention window; a founder's personal laptop that gets replaced in year three is a common way this evidence quietly disappears.

For the full picture of which directives feed into your file, see our CE marking requirements overview, or run your specific product through the free requirements checker.