CE/UKCA test, passed.
Also called: Compliance testing · Conformity assessment · Safety and EMC testing · Type testing
The formal safety, EMC and product-specific tests a product must pass on representative units before it is legal to sell.
Send representative production units for the tests that gate sale: electrical safety, EMC, and anything product-specific. Fix what fails, retest, and keep the reports. Those reports support the UKCA mark and the Declaration of Conformity. No reports, no legal sale.
What CE/UKCA testing is
CE/UKCA testing is the set of formal tests a product must pass before you are allowed to sell it. For a mains-powered electrical product that means, at minimum, electrical safety testing against the relevant BS EN standard, and EMC testing to check the product neither emits interference nor falls over when something nearby does. Some products carry extra, category-specific tests on top. Pass them all, document the results, and you have earned the mark. Fail one, and you cannot legally put it on the shelf.
The word that does the work here is representative. The unit on the test bench has to be the unit a customer will actually receive: production-intent build, production firmware, production enclosure. A hand-soldered lab prototype that passes proves nothing about the boxes coming off the line. The test result is only as honest as the sample it ran on.
What actually gates the sale
- Electrical safety. For a mains product, testing against a BS EN 61010-type requirement: insulation, earthing, creepage, temperature rise, the things that decide whether the product can kill someone. Non-negotiable.
- EMC. Emissions (does it pollute the radio spectrum?) and immunity (does it survive a nearby spike or transient?). In my experience this is where the surprise failure usually hides, because it depends on layout and cabling, not just the schematic.
- Product-specific tests. Whatever the product’s category demands on top. A heated kitchen appliance has thermal and surface-temperature expectations a generic gadget does not.
None of this is design work. By this point the design is frozen. This activity is the exam: you find out whether the engineering you did across Stage 06, Stage 07 and the rest of Stage 08 actually holds up under measurement.
How testing played out on the proofing box
The proofing box is a sub-30W mains appliance at £149, so the two compulsory tests were electrical safety and EMC. We worked through both on representative units rather than the bench prototype, found one EMC issue, fixed it, and retested. Here is the shape of it.
The lesson Dan took from it: the failure was not a disaster, it was data. One marginal line, found in a controlled test, fixed for the cost of two components. Far cheaper here than after a thousand units had shipped.
The trap, and the better move
- Test at the very end and pray.
- Send the lab prototype, not a real production unit.
- Treat a fail as a catastrophe instead of a finding.
- Lose the reports, so the mark has nothing behind it.
- Test representative units, fix what fails, document.
- Design with the standards in mind, so testing confirms rather than surprises.
- Budget for one retest from the start.
- File every report in the technical file as you go.
How it fits the bigger picture
CE/UKCA test is activity 08.20.05 in the framework, and it is the last activity of Stage 08 Develop. It depends on a frozen design and a representative production build, and it closes Develop by proving the product is legal to sell. With the reports filed and the mark earned, the project moves into Stage 09 Manufacture, where the question shifts from “is this one unit compliant?” to “does every unit off the line match the one that passed?”.
What it can do
It tells you, with measured evidence, whether the product can legally and safely be sold. It produces the reports that back the UKCA mark and the Declaration of Conformity, and it catches the marginal failures while they are still cheap to fix.
What it can’t do
It can’t guarantee every future unit is identical to the one tested; that is what production control and inspection in Stage 09 Manufacture exist to hold. And it can’t rescue a product that was never designed against the standards. Test late on a non-compliant design and you buy yourself a redesign, not a mark.
See the full 10-stage process →
Try it yourself
List the directives and standards your product falls under (for a mains electrical product, start with safety and EMC). Find an accredited test house and get a quote against representative production units, not a prototype. Build one retest into the budget and timeline before you start, because something usually needs a tweak. Then file every report as it lands.
Not sure which tests apply to your idea yet? Start the Free Sprint → and map the compliance route before you commit to tooling.
Your compliance-test checklist
Project notes: one EMC line over the limit
▸ From the notebook · optional reading
Sending representative units to test with Dan and Anna in Stockport, the one EMC line that failed, and the two-component fix that cleared it.
3 min read · click to open
By the time we booked the test slot, the design was frozen and the boards from the Manchester PCB house were the real production build. I was firm with Dan on one point: “We test the unit a customer gets, not the tidy one on my bench.” So we sent three representative units up to the lab.
Electrical safety
The BS EN 61010-type safety testing passed on the first pass. A sub-30W mains appliance with proper earthing, sensible creepage and a controlled temperature rise was never going to be the hard part, and it wasn’t. Clean report, filed.
EMC, and the one line that failed
EMC was where it got interesting. Immunity was fine. Radiated emissions were fine. But conducted emissions sat marginally over the limit at the heater switching frequency, one narrow line poking above an otherwise clean sweep. Dan’s face dropped. I told him what I tell every founder at this point: a fail in a test house is the cheapest fail you will ever have.
The fix was unglamorous. A small mains-input filter and a soft-start on the heater drive to soften the switching edges. Two components and a board respin from Manchester. On retest the line dropped comfortably under the limit. Total cost of the problem: a few pounds of parts and about a fortnight.
The reports are the point
What we walked away with mattered more than the pass itself: two signed test reports. Those went straight into the technical file as the evidence behind the UKCA mark and the Declaration of Conformity Anna signed off. Without the reports, the mark would have been a sticker with nothing behind it. With them, the proofing box was legal to sell, and Develop was done.
— Develop stage, project notes, 2026
— Next stage → Stage 09 · Manufacture