Unlisted or imported electrical equipment is approved one of two ways: the manufacturer obtains a certification an American inspector recognises, or you pay a qualified body to evaluate that particular unit on site and label it. There is no third route. A European CE mark, a foreign test report and a supplier’s word are not approval.
In short
- The code word that decides everything is approved, and the National Electrical Code defines it as “Acceptable to the Authority Having Jurisdiction”. Your inspector is the authority, not a laboratory.
- A CE mark is not a listing. UL states plainly that CE marked products “are not considered to be Listed as defined in NFPA and ICC model codes and standards”.
- The rescue route is a field evaluation: an on site assessment of “new, unlabeled or modified equipment”, ending in a serialised label. NFPA 790 governs the bodies and NFPA 791 the procedure, which must be completed and labelled at the final installation site.
- A Canadian evaluation does not travel south: it is written against the Canadian Electrical Code, and the governing Canadian standard “does not apply to the United States”.
- On a small residential job the process costs more than the equipment. Deciding before you import is always cheaper than deciding after.
Approved does not mean listed, and the difference is the whole problem
In American practice, approval is a decision taken by a person, not a property a product carries. The National Electrical Code, published as NFPA 70, defines Approved in Article 100 as “Acceptable to the Authority Having Jurisdiction”, and section 110.2 requires that conductors and equipment be approved.
Listing is different. It is a finding by a testing organisation that a product type conforms to a product safety standard, recorded in a published list and marked on every unit produced under that organisation’s surveillance. Listing is evidence. Approval is the verdict. Inspectors accept listing because it is the cheapest evidence available to them, which is why the two words get used as if they meant the same thing. Put unlisted equipment on the wall and they come apart, and you are in the business of persuading a person.
NFPA defines the authority having jurisdiction as “an organization, office, or individual responsible for enforcing the requirements of a code or standard”. Which office that is depends on where you are building. We worked through how to find yours in do you need a permit and a licensed electrician, and the structure there holds here: the right to do the work is a state question, the duty to declare it is a local one.
The three words an inspector is actually using
Most arguments on site come from mixing these three up. Separate them and the conversation gets short.
| Word | What it describes | Who decides it |
|---|---|---|
| Listed | A product type appears in a list published by a qualified testing organisation | The testing organisation |
| Labeled | This unit carries that organisation’s mark, under ongoing factory surveillance | The manufacturer, under the organisation’s control |
| Approved | Acceptable to the authority having jurisdiction, on this job | Your inspector |
Note what is missing from that table: the seller. A product page, a specification sheet and a customer service email are none of the three. Ask for the file number and the issuing organisation, in writing, before you order anything.
Why a CE mark will not get you through an inspection
A CE mark answers a European legal question and carries no weight in a US inspection. UL describes the CE mark as “usually a manufacturer’s self-declaration”, and states that CE marked products “are not considered to be Listed as defined in NFPA and ICC model codes and standards”.
That is not a slight on European manufacturing but a statement about who did the assessment. A self declaration against European directives is not a third party finding against the American standard the inspector is working from, and the inspector has no mechanism for treating it as one.
The same page tells you how to check a claim. “UL Listed products are required to carry a marking to identify the Listed company”, a certification can be verified in UL’s product database, and where a listing does not appear there “the manufacturer should be able to provide documentation from UL confirming the certification”. A compliance claim absent from the database and unsupported by a file is a self declaration that “has not been verified by an independent third party”. If a supplier cannot give you a file number, treat the product as unlisted and budget accordingly.
What a qualified testing organisation has to be
The federal definition worth quoting is OSHA’s, because it is free to read and precise. 29 CFR 1910.7 defines a nationally recognized testing laboratory as “an organization which is recognized by OSHA” that “tests for safety, and lists or labels or accepts, equipment or materials”, and sets four criteria it must meet.
| OSHA criterion | What the text requires |
|---|---|
| Capability | The testing equipment, trained staff, written procedures and calibration and quality control programmes to carry out “testing and examining of equipment and materials for workplace safety purposes” against the appropriate test standards |
| Controls and services | Procedures identifying the listed and labelled items, inspection of “the run of production of such items at factories”, and field inspections to “assure the proper use of its identifying mark or labels on products” |
| Independence | “Completely independent of employers subject to the tested equipment requirements” and of any manufacturer or vendor of the equipment tested |
| Procedures | Effective procedures for “producing creditable findings or reports that are objective and without bias” and for handling complaints “under a fair and reasonable system” |
Two consequences follow for anyone importing. Recognition is granted for named scopes rather than wholesale, so a mark from a real laboratory outside its recognised scope will not help you. And the factory surveillance requirement is why a one off test report is not a listing: a listing is a continuing arrangement with the factory, a report is a photograph of one sample on one day.
The rescue route: what a field evaluation is
A field evaluation is how equipment that is already installed gets approved. UL describes it as “an on-site assessment that determines whether new, unlabeled or modified equipment meets applicable safety standards”, applying to uncertified equipment and to equipment “that has been customized or modified after certification”.
If the equipment passes, “a UL Evaluated Label will be immediately applied”; if not, you get “a detailed preliminary findings report citing each issue”. The label is site specific, because the assessment looks at the equipment “for the specific application and location where the product is being utilized”, so it says nothing about the next unit you import. Authorities “may mandate a field evaluation before allowing the equipment to be energized”, and the service “is an accepted approach by local code authorities”.
Where a field evaluation differs from a listing
Treat them as two different products with two different values, because that is how an inspector reads them. The cost line is the one that changes decisions.
| Question | A listing | A field evaluation |
|---|---|---|
| What is assessed | A product type, by sample, in a laboratory | This particular unit, as installed |
| Where it happens | The laboratory, plus ongoing factory surveillance | “Performed on-site where products are installed and operated” |
| What you receive | A certification mark on every unit produced | A serialised label on that one unit, with a matching report |
| Who it satisfies | Inspectors generally, anywhere in the country | The authority on that job, which receives the report |
| Cost behaviour | Paid once by the manufacturer, spread over production | Paid per visit, by you |
| Governing document | The product safety standard | NFPA 791, and the product standard it points to |
A field evaluation is priced as a site visit by a qualified engineer plus a report, so on a single switch it will exceed the value of the equipment several times over, while on a commercial assembly it is routine and proportionate. We publish no figure: the quotes are per job and we are not the people quoting them.
NFPA 790 and NFPA 791, the two documents behind the label
Knowing these two names is worth real money in a conversation with an inspector. NFPA 790 is the “Standard For Competency Of Third-Party Field Evaluation Bodies”, and NFPA 791 is the “Recommended Practice And Procedures For Unlabeled Electrical Equipment Evaluation”. Together they “offer a recommended framework for managing the evaluation and labeling process for uncertified electrical equipment”.
A field evaluation body is “an organization or part of an organization that performs field evaluations”, and such bodies “evaluate unlisted electrical equipment to determine compliance with national product safety standards”. Field evaluations “fill the gap for equipment that is not subject to a traditional certification or safety listing”. So ask any body you engage which accreditation it holds against NFPA 790 and whether it works to NFPA 791. If it cannot answer, you are buying a report your inspector may decline.
A Canadian evaluation does not travel south
This trips up buyers who find a cheaper route through Canada. The Canadian field evaluation standard, SPE-1000, “only applies to products intended to be installed in Canada in accordance with the Canadian Electrical Code, Part 1”, and as UL puts it, SPE-1000 “does not apply to the United States”.
The procedures differ in a way that matters. Under the Canadian standard, evaluation and labelling may happen at the factory or in the field, and need not happen at the final installation site. In the United States, NFPA 791 requires the process to be “completed and labeled at the final installation site”, using the applicable product safety standard and the NEC. A Canadian label is “recognized and accepted by the Canadian Electrical Authorities across Canada”, and that is the territory it describes.
The reverse holds too, and it costs us money rather than you: a certification covering the United States does not automatically cover Canada, and a Canadian inspector is entitled to ask for Canadian evidence. More on our own position below.
The procedure, step by step
Seven steps, in this order. Doing them out of order is how people end up paying twice.
- Get the objection in writing. Ask which code section the equipment fails and what evidence would satisfy them. An inspector asking for a listing and one asking for a field label have asked for two different things at two different prices.
- Find out which product safety standard applies. A field evaluation runs against a named standard for that category. Without it, nobody can quote you.
- Ask the manufacturer for its certification file: the issuing organisation, the file number and the scope. Check it in the certifier’s public database. Many imported products hold a certification nobody at the reseller knew about.
- Decide between evaluating and substituting. Price the evaluation against a listed product that does the same job. On small residential items substitution wins, by a wide margin.
- Engage an accredited field evaluation body. Confirm its accreditation against NFPA 790 and that it works to NFPA 791. Give it your inspector’s name and jurisdiction at the outset.
- Present the equipment installed and de-energised. The engineer needs access to terminations, markings and nameplate data, and the manufacturer’s documentation on site.
- Give the report to the authority having jurisdiction. The AHJ is among the parties the procedure names, and the report forms part of the approval decision. Keep the label number with the project record.
Nothing in that sequence requires you to touch a live conductor, and nothing in it substitutes for a permit.
When a licensed electrician and a permit are not optional
Approval of the equipment and permission to do the work are separate questions, and unlisted equipment tends to arrive with both.
Treat a licensed electrician and a permit as mandatory, not advisable, whenever the job opens a wall, alters a circuit, adds or moves a box, changes a circuit’s rating, or extends wiring. Many jurisdictions exempt a like for like device swap and allow a homeowner to do it, within limits, in a home they own and occupy. Installing equipment the inspector has not approved is not a like for like swap, and an unlisted device is a poor candidate for that exemption. Confirm the rule with your building department rather than a forum: it is written locally and amended often.
One quieter consequence: work that was never permitted and equipment that was never approved both show up later, at resale, at an insurance claim, or at the next permit application on the same property.
Before you touch anything
Switch off the breaker that feeds the circuit, then verify that the conductors are dead with a meter before your hands go near them. Not a non contact pen alone, and never the switch itself as proof: a switch can interrupt one conductor while another in the same box stays live. Lock or tag the breaker if anyone else can reach the panel.
Then consider the building. In anything built before 1978 the paint around a box may contain lead, and disturbing it brings federal renovation rules into play. In an older house there may be no equipment grounding conductor at all, which changes what you may install and what a metal plate means: see upgrading switches with no ground wire. Box depth and fill are their own question, covered in electrical box types and sizes and how many outlets can be on one circuit. If any of that is unfamiliar, this is work for a licensed electrician.
Where Studio Timeless stands, in plain terms
We sell both kinds of product, and we would rather you heard this from us than from an inspector.
Our knurled toggle switches carry a cULus listing, file E313169, read from the marking on the module itself, valid in both the United States and Canada, and the Double USB-C outlet is also cULus. Our Retro Toggle range is CE marked and not UL or ETL listed. On the reading of the UL page above, it is not Listed as the model codes define the term, and an inspector is entitled to refuse it. If your job will be inspected and you want a lever, specify the knurled range. Our rotary dimmers hold a UL file, which we state without a number because we will not publish a number we have not read off the part, and they carry no Canadian certification. A Canadian buyer cancelled a dimmer order with us this month for that reason, and we had nothing to offer in its place.
Two further limits. We will not confirm that another manufacturer’s mechanism fits behind our plates or inside our units without written confirmation from that manufacturer, whatever a dimension suggests; the installation and compatibility guide is where those questions go. And we do not offer, arrange or pay for field evaluations. If your authority asks for one on a Studio Timeless product, tell us through contact and we will send the documentation we hold, which is the useful part of what we can do.
Four questions to settle before you import anything
Ask these before money moves, in this order, and the expensive surprise disappears. First, which organisation certified it, and what is the file number? No answer means unlisted. Second, does the certification cover the United States, and my country? A mark naming one country is evidence about that country. Third, does my inspector accept a field label for this category, and when do they want to see it? Fourth, what is the listed alternative, and what does it cost? Until you have priced it you cannot tell whether an evaluation is worth buying.
They also work as a filter on brands rather than products. Several well known European switch makers sell into the United States without naming a certification on their public pages, which we noted in where to buy Forbes and Lomax in the United States and in our comparison of Residence Supply and Buster and Punch. An absence of a claim is not a claim of absence, and not a reason to assume the worst. It is a reason to ask the first question before the pallet ships, and the same discipline applies to the cheaper lookalikes of a well known brand, where a false mark is a real risk.
If the inspector has already said no
You have four moves, in rising order of cost. Produce a certification nobody had looked for, which works more often than you would think. Buy a field evaluation, when the equipment is sound and worth the visit. Substitute a listed product, the right answer on most residential items. Or appeal, which exists in most jurisdictions and is slow.
What does not work is energising it anyway. Price the replacement module route first: swapping a mechanism for a listed one while keeping the brass you chose is often cheaper than any of the four, as we explained in repair instead of replace.
Frequently asked questions
Is it illegal to install unlisted electrical equipment?
The usual position is not that it is illegal to own or sell, but that it cannot be approved, and the code requires equipment to be approved. That makes an unapproved installation a failed inspection rather than a crime. Your jurisdiction decides, so ask your building department.
Does a CE mark count in the United States?
No. UL describes the CE mark as usually a manufacturer’s self-declaration and states that CE marked products are not considered to be Listed as the NFPA and ICC model codes define the term.
What is the difference between UL Listed and UL Recognized?
A listing applies to a complete product assessed for field installation. Recognition applies to a component assessed for use inside someone else’s end product, within stated conditions. A recognised component is not a listed product, which matters when a supplier quotes a file number without saying which kind it is.
How much does a field evaluation cost?
It is quoted per job, because it is a site visit by a qualified engineer plus a report. We publish no figure and would be inventing one. The useful rule is that on a single residential device it usually costs more than buying a listed product instead.
Can I get a field evaluation before the equipment is installed?
For a US evaluation, not in the usual case. NFPA 791 requires the process to be completed and labelled at the final installation site, which is one of the clearest differences from the Canadian procedure.
Will a Canadian certification satisfy an American inspector?
Do not plan on it. The Canadian field evaluation standard applies to products intended for installation in Canada under the Canadian Electrical Code and does not apply to the United States. A combined mark such as cULus is different, because it names both countries.
Who is my authority having jurisdiction?
Usually the electrical inspector at your city or county building department, sometimes a state office, and on some sites an insurer. NFPA defines it as the organisation, office or individual responsible for enforcing the code. Call the building department and ask by name.
Are Studio Timeless switches listed?
Our knurled toggle range carries a cULus listing, file E313169, valid in the United States and Canada, and the Double USB-C outlet is also cULus. Our Retro Toggle range is CE marked and not UL or ETL listed, so an inspector may refuse it. Our rotary dimmers hold a UL file and no Canadian certification.
Can I use a European switch mechanism behind one of your plates?
We will not confirm that, and no dimension on a page should be read as confirmation. Our units are single-piece assemblies rather than a plate plus a separate device, so there is usually nothing to put a third-party mechanism into.
Does a permit cover the equipment as well as the work?
No. A permit authorises the work and triggers inspection. Approval of the equipment is a separate finding made at that inspection. You can hold a valid permit and still fail on an unlisted device.
Where to go from here
If the equipment is already bought, start with step three and look for a certification file before you pay for anything. If it is not bought yet, ask the four questions. Where a listed brass device is what you need, our toggle switch range and the wider switches and outlets collection are the place to start, and we will send what we hold before you specify it. Companion piece for today: what gunmetal and French gold actually mean, on the same principle that the page copy is not the contract.
This article explains how approval works in the United States. It is not legal advice, and it does not substitute for your local code, your permit or your inspector’s ruling.
Last updated: 18 October 2026.
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