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Regulation and sustainability

The product's technical file

The declaration of conformity is the cover page. The technical file is what sits behind it, and it is what gets asked for when someone doubts.

Updated on 13/08/2026

A declaration of conformity fits on one page and is signed in a minute. That is why it gets signed cheerfully. What almost nobody looks at on signing day is the awkward question behind it: **and on what basis?** The set of answers to that question is the technical file.

Technical file

The set of documents showing WHY the product complies: tests, calculations, drawings, standards applied and the risk assessment. It does not ship with the product; it is kept and produced on request.

What it usually holds, and where it usually fails

PieceWho holds itWhere it gets lost
Laboratory test reportsThe lab and youLeft in the inbox of whoever commissioned it
Risk assessmentWhoever designed itNever written down — it was «done mentally»
Drawings for the version soldEngineeringThe new drawing exists; the sold version's does not
Standards applied and their editionQualityThe standard was cited without saying which year
Documentation for bought-in componentsPurchasingEach supplier sends their own format and it scatters

Important

The mistake that turns this into a serious problem is one of timing: **the file gets assembled when someone asks, and by then half of it is missing**. The lab closed, the engineer who did the calculations left, the component supplier changed hands. None of that is recoverable afterwards. A technical file is built the day the declaration is signed, not the day the question arrives — because on the day the question arrives you can no longer manufacture the past.

Building it so it outlives the people

  1. 1

    One file per product and per version

    «The file for model X» without a version is the door to producing the wrong paper.

  2. 2

    Every document dated and attributed

    A test report with no date and no identifiable lab supports nothing.

  3. 3

    The edition of the standard, not just its number

    Standards get revised; citing the 2014 one when 2021 applied is a classic.

  4. 4

    And component documentation inside, not linked

    A link to the supplier's website expires when they redesign it.

Watch out

One costly confusion, easily undone: **the instruction manual is not the technical file**. The manual travels with the product and is read by the customer; the file stays with you and is read by whoever investigates. Mixing them means over-delivering to customers —including calculations and supplier names you would rather not publish— and missing what actually matters when the question comes from an authority.

And how long it is kept

Worth knowing

Exactly what the file must contain, who may demand it and for how many years it must be kept depends on the product type and the rules applying to it. **Your adviser or notified body settles that**; here we explain why it is assembled on signing day and not on question day.

Do I have to hand the file to my customers?

Normally no: it is kept and shown to those entitled to ask for it.

Are my suppliers' certificates enough?

They are one part. The file explains your product, not only its pieces.

What if someone else manufactures for me?

Then agree in writing who keeps what, before you start selling.

A real case

The situation

An authority asks for the file on a product sold four years ago and the testing laboratory no longer exists.

What you do

  1. Keeps a copy of each test report in the file the day it arrives, not a link to the lab

What you get

The file stays complete even though the test provider has vanished.

The situation

The model X file is produced and turns out to be the current version's, not the unit sold.

What you do

  1. Opens one file per version and freezes each at launch

What you get

Every unit sold has the documentation that belongs to it behind it, not someone else's.

The situation

The engineer who ran the calculations has left and nobody can find the risk assessment.

What you do

  1. Requires the assessment to be written and filed before the declaration is signed

What you get

What lived in one person's head moves into the company's file.

The situation

The declaration is issued and there is no file behind it.

What you do

  1. Gathers what backs it into one file

What you get

The cover page has what supports it behind.

The situation

The file lives on the machine of whoever made it.

What you do

  1. Stores it off personal machines

What you get

Somebody leaving does not take the file.

The situation

The file is requested and a supplier's contribution is missing.

What you do

  1. Keeps third-party material with its own

What you get

The file is complete.

This article answers

  • what is a product technical file
  • what documentation to keep for a product i make
  • asked for the technical file
  • how long to keep technical documentation