What is the difference between a test laboratory and a certification body?

A test laboratory measures the product against a standard and issues a test report with results, expanded uncertainty and a pass or fail statement. A certification body reviews evidence (often that very report) against a scheme and issues a certificate or attestation that the product conforms. Testing produces data, certification produces a decision. The two functions can sit in one organisation but they are accredited under different standards, ISO/IEC 17025 for the lab and ISO/IEC 17065 for the certification body.

Is a Notified Body the same thing as an accredited laboratory?

No. A Notified Body is a conformity assessment body that a Member State has formally designated and notified to the European Commission to carry out third-party tasks under a specific EU directive or regulation. It is a legal status tied to a piece of EU legislation. An accredited laboratory holds a technical competence attestation under ISO/IEC 17025 from a national accreditation body. Most Notified Bodies are accredited, but accreditation alone does not make a lab a Notified Body, and not every accredited lab is notified.

Why is an accredited test report accepted in other countries?

Because national accreditation bodies sign mutual recognition arrangements. The ILAC MRA covers testing, calibration and inspection, and the IAF MLA covers certification and management systems. When a lab is accredited by a signatory and the relevant scope is in the arrangement, its report carries the principle "tested once, accepted everywhere". This does not override mandatory national approval steps, but it removes the need to repeat the underlying measurements.

What is an NRTL and how does it relate to a Notified Body?

An NRTL (Nationally Recognized Testing Laboratory) is a body recognised by OSHA in the United States to test and certify products for workplace safety against US standards such as UL 62368-1. It is the rough US analogue of the EU safety route, but the legal mechanism is different: OSHA recognition and a listing mark (UL, ETL) rather than EU designation and CE marking. NRTL recognition and EU notification are separate systems with separate scopes.

Can I use in-house or non-accredited test data in my technical file?

Sometimes. Under self-declaration routes (CE module A, FCC SDoC) the manufacturer may rely on its own measurements, provided the equipment is calibrated and the method follows the standard. The risk is that market surveillance, a customer audit or a Notified Body can challenge non-accredited data more easily, and it carries no cross-border recognition. Where a directive requires third-party involvement, or a scheme requires accredited testing, in-house data is not sufficient on its own.

What is a TCB in the US FCC system?

A TCB (Telecommunication Certification Body) is a body accredited under ISO/IEC 17065 and recognised by the FCC to grant equipment authorisation (Certification) for intentional radiators. It issues the grant and the product receives an FCC ID. The TCB plays a role broadly comparable to a Notified Body issuing an EU-type examination certificate, but within the FCC framework and the 47 CFR rules.

Which accreditation standard applies to whom?

ISO/IEC 17025 applies to testing and calibration laboratories. ISO/IEC 17065 applies to bodies that certify products, processes and services. ISO/IEC 17020 applies to inspection bodies, and ISO/IEC 17021-1 applies to bodies certifying management systems (for example ISO 9001 registrars). Picking the right standard tells you what competence the body actually holds and what its accreditation certificate covers.

How do I qualify a test laboratory before sending it a product?

Ask for the accreditation certificate and, crucially, the scope annex. The scope lists the exact standards, parameters and ranges the lab is accredited for. Confirm the standard and revision you need is on that scope, check the accreditation body is an ILAC MRA signatory, verify the calibration status of the equipment, agree the report format, and confirm lead time and the working language. An accredited stamp on a report outside the lab's scope is worthless.

Conformity assessment bodies and accreditation

Author Hugues Orgitello Last updated 31 May 2026 ~12 min read

Guide · Who tests, who certifies, who accredits

One of the first orientation gaps in any certification project is the confusion between the organisations involved. A test laboratory, a certification body, a Notified Body, an NRTL, a TCB, these are not interchangeable names for "the people who certify". They have different jobs, sit under different accreditation standards, and carry different legal weight. This page maps the ecosystem: what each body actually does, what accreditation means and why it matters, how the national accreditation bodies and the international mutual recognition arrangements make a report travel across borders, and how to choose and qualify a laboratory. It deliberately stays separate from the question of which assessment module to pick and which specific body to engage.

The vocabulary problem

Manufacturers routinely say "we sent it to the certification lab", "the Notified Body tested it", or "we need an accredited certificate". Each of those phrases blurs two distinct functions. Untangling them is the whole point of this page.

The two atomic activities are testing and certification:

Testing is measurement. A laboratory puts the product on a bench, applies the procedure defined by a standard, and reports numbers: emission levels, immunity pass or fail, temperature rise, the expanded uncertainty on each value. A test report is evidence, not a verdict on conformity.
Certification is a decision. A body reviews evidence against a defined scheme and issues a certificate or attestation stating that the product (or process, or system) conforms. Certification consumes test reports; it does not usually generate the raw measurements itself.

Everything else is a label for an organisation that performs one or both of these activities under a particular legal or contractual framework.

Conformity Assessment Body: the umbrella term

Conformity Assessment Body (CAB) is the generic term that covers all of them. ISO/IEC 17000 defines conformity assessment as the demonstration that specified requirements are fulfilled, and a CAB is any body that performs such activity: testing, calibration, inspection, product certification, or management-system certification.

A CAB becomes something more specific the moment a legal or contractual framework recognises it for a defined task:

When a CAB is...	It is called	Recognised by	Under
Designated for an EU directive	a Notified Body (NB)	an EU Member State, listed in NANDO	EU New Legislative Framework
Recognised by OSHA in the US for safety	an NRTL	OSHA	29 CFR 1910.7
Recognised by the FCC for radio grants	a TCB	the FCC	47 CFR
Accredited to test or calibrate	an accredited laboratory	a national accreditation body	ISO/IEC 17025
Accredited to certify products	a certification body	a national accreditation body	ISO/IEC 17065

The key insight: "Notified Body", "NRTL" and "TCB" are recognition statuses, not accreditation standards. Accreditation is the technical foundation; recognition is the legal authorisation built on top of it. A single organisation, say a large TÜV or Bureau Veritas entity, can simultaneously be an accredited 17025 laboratory, an accredited 17065 certification body, a Notified Body for several directives, an NRTL, and a TCB. The role it plays depends on which hat it is wearing for a given job.

What accreditation actually means

Accreditation is third-party attestation that a conformity assessment body is technically competent and impartial to perform specific tasks. It is itself a conformity assessment activity, one level up: the accreditation body assesses the CAB the way the CAB assesses products.

Three properties define a meaningful accreditation:

It is granted by a recognised national accreditation body, not self-claimed. In the EU, Regulation 765/2008 establishes that each Member State designates a single national accreditation body operating not-for-profit.
It is against a published standard from the ISO/IEC 17000 family, so the requirements are objective and the same everywhere.
It is scoped. An accreditation certificate is always accompanied by a scope annex listing the precise standards, parameters and measurement ranges covered. Competence outside that scope is simply not accredited.

The accreditation standards, by activity

This is the table that resolves "which 170xx applies":

Standard	Applies to	Output
ISO/IEC 17025	Testing and calibration laboratories	Test report, calibration certificate
ISO/IEC 17020	Inspection bodies	Inspection report
ISO/IEC 17065	Product, process and service certification bodies	Product certificate / attestation
ISO/IEC 17021-1	Management-system certification bodies	ISO 9001 / 27001 certificate
ISO/IEC 17024	Bodies certifying persons	Personnel certificate
ISO/IEC 17011	Accreditation bodies themselves	Accreditation of the CAB

The two that dominate electronics certification are 17025 for the lab that measures and 17065 for the body that certifies the product. ISO/IEC 17025 covers competence of staff, validity of methods, calibration and metrological traceability, handling of measurement uncertainty, and integrity of reporting. ISO/IEC 17065 covers the certification decision process, impartiality safeguards, and the scheme rules the body applies.

A common confusion is 17025 versus 17020 versus 17021. They are not tiers of quality; they are different activities. A 17020 inspection body looks at conformity in the field or at intervals (think installations, periodic checks); a 17021 body audits a management system, not a product. Asking a 17021 registrar to "certify your product" is a category error.

Why accreditation matters: the chain of trust

Accreditation exists so that a buyer, a regulator or a Notified Body in another country can trust a report they did not witness. The trust travels through a chain:

International metrology (the SI units, BIPM) → calibration laboratories → accredited test laboratories → accreditation bodies → mutual recognition arrangements → acceptance worldwide.

Two mechanisms make the last step work, and they are the reason an accredited report is portable.

The ILAC MRA (testing, calibration, inspection)

The International Laboratory Accreditation Cooperation operates the ILAC MRA, a multilateral arrangement among national accreditation bodies. When your laboratory is accredited by an ILAC MRA signatory and the relevant scope is included, the principle is "tested or calibrated once, accepted everywhere". A report bearing the ILAC MRA combined mark plus the accreditation body symbol signals this to a foreign reviewer.

The IAF MLA (certification, management systems)

The International Accreditation Forum (IAF) operated the IAF Multilateral Recognition Arrangement, the equivalent for product certification (17065), management-system certification (17021) and personnel certification (17024). IAF ceased operations on 1 January 2026 and merged with ILAC to form Global Accreditation Cooperation Incorporated, which maintains the existing MLA arrangements.

In Europe, the European co-operation for Accreditation (EA) is the regional body that coordinates the national accreditation bodies of the EU/EEA and operates the EA MLA, which feeds into ILAC and IAF. EA is the regional layer that gives the whole single market a single accreditation backbone under Regulation 765/2008.

The practical consequence is concrete: a report from a COFRAC-accredited lab in France, with the standard in scope, does not need to be repeated when the same product is assessed by a Notified Body in Germany or submitted to a TCB-recognised path that accepts ILAC data. The measurements are reused; only the decision step is repeated where the framework requires it.

National accreditation bodies

Each economy has a single (or few) recognised accreditation body. These are the organisations that actually issue the 17025 / 17065 accreditation certificates and sign the MRAs on behalf of their country.

Body	Country	Member of
COFRAC	France	EA, ILAC, IAF
UKAS	United Kingdom	ILAC, IAF (and EA arrangements)
DAkkS	Germany	EA, ILAC, IAF
ACCREDIA	Italy	EA, ILAC, IAF
ENAC	Spain	EA, ILAC, IAF
RvA	Netherlands	EA, ILAC, IAF
A2LA	United States	ILAC, IAF
NVLAP (NIST)	United States	ILAC
SCC	Canada	ILAC, IAF

When you read a laboratory's accreditation certificate, the logo at the top tells you which national body backs it, and therefore which MRAs the report inherits. A report accredited by a body that is not an ILAC MRA signatory does not travel; treat it as in-house data for cross-border purposes.

The regional analogues: EU, US

The same testing-then-certification split exists in every major market, but the recognition layer wears local names. Distinguishing them avoids the classic mistake of assuming a CE-route body can grant a US authorisation.

European Union

Under the New Legislative Framework, third-party tasks are done by Notified Bodies, designated by a Member State and listed in the Commission's NANDO database. An NB issues, for example, an EU-type examination certificate. Behind the NB, the actual measurements are usually run in a ISO/IEC 17025 laboratory, and the NB itself is generally accredited under ISO/IEC 17065 or 17020 for its certification or inspection activity. For how to read NANDO scopes and pick the right NB, see notified body selection, and for what the NB does after certification see notified body surveillance audits.

United States, safety

Workplace product safety is governed by OSHA, which recognises NRTLs (Nationally Recognized Testing Laboratories) to test and certify against US safety standards such as UL 62368-1. The product carries a listing mark (UL, ETL by Intertek, CSA). There is no "self-declared" route for the OSHA NRTL scheme the way module A exists for CE safety, recognition by OSHA and a listing mark are the mechanism.

United States, radio

Radio equipment authorisation is run by the FCC. For intentional radiators, a TCB accredited under ISO/IEC 17065 and recognised by the FCC grants Certification and the product receives an FCC ID. For many unintentional radiators the manufacturer uses SDoC, the FCC self-declaration analogue, with testing in an FCC-recognised accredited lab. The TCB grant is broadly the US counterpart of an EU-type examination certificate, within the 47 CFR framework.

The point of laying these side by side: the legal status (NB, NRTL, TCB) is market-specific, but the accreditation underneath them is the common, portable layer. That is why a single test campaign in a well-scoped 17025 lab can feed a CE file, a UL listing and an FCC grant in parallel.

How to choose and qualify a test laboratory

Selecting a lab is a due-diligence exercise, not a price comparison. The single most common failure is accepting a report whose accredited scope does not actually cover the standard you needed.

The checklist

Get the accreditation certificate and its scope annex. The certificate alone is marketing. The scope annex is the contract: it lists the exact standards, revisions, parameters and ranges the lab is accredited for. Confirm the standard and revision you need appears there.
Check the accreditation body is an ILAC MRA signatory if you need cross-border recognition. Otherwise the accredited stamp buys you nothing outside that country.
Verify metrological traceability and calibration status. Accredited results depend on calibrated equipment with traceability to SI units and a stated measurement uncertainty. For how that uncertainty is built and reported, see calibration and measurement uncertainty.
Confirm the report will carry the accreditation mark for the tests you ordered. A lab can run accredited and non-accredited tests in the same building; some line items on the quote may be outside scope. Have them flag which results are accredited.
Agree the deliverable format up front. A Notified Body or a TCB expects a report in a recognisable structure with full configuration description, uncertainty and traceability. A thin "we tested it, it passed" memo is not acceptable evidence.
Check capacity, lead time and the working language. Chamber and bench time is the usual bottleneck; quoted weeks become months in peak periods.
Confirm pre-scan and engineering support. A good lab offers non-accredited pre-compliance scans to find problems before the formal accredited run, which is far cheaper than a failed campaign.

What the accredited scope annex looks like

A scope line is specific. It does not say "EMC testing"; it says, for example, radiated emissions per EN 55032 over 30 MHz to 6 GHz with a stated uncertainty, or electrical safety per EN 62368-1 for given clauses. If your product needs a standard or a frequency range not on that line, the lab is not accredited for it, regardless of how capable the engineers are.

In-house testing versus accredited external testing

A frequent and legitimate question: can the manufacturer use its own measurements? The answer depends on the route and on who will challenge the data.

Aspect	In-house / non-accredited	Accredited external
Allowed for self-declaration (CE module A, FCC SDoC)?	Often yes, if method and calibration are sound	Yes
Accepted by a Notified Body / TCB on its own?	Usually no	Yes
Cross-border recognition (ILAC / IAF)?	None	Yes, within scope
Robustness to market-surveillance challenge	Weaker, easy to contest	Strong
Typical use	Pre-compliance, design iteration, internal QA	Formal compliance evidence, type certificates
Cost per campaign	Lower marginal cost, high equipment capex	Higher per run, no capex

The defensible strategy for most electronics teams is non-accredited pre-compliance in-house, accredited testing for the formal record. In-house pre-scans catch the expensive surprises early; the accredited run produces the report that survives an audit and travels across borders. The limit of non-accredited data is precisely its weakness under challenge and its lack of cross-border standing, the moment a directive requires third-party assessment, or a scheme requires accredited testing, in-house data alone will not carry the file.

A related pitfall: a manufacturer integrating a pre-certified radio module sometimes assumes it inherits the module's accredited test data wholesale. It does not. The host product still needs its own accredited assessment for emissions, safety and exposure as integrated; the module report is an input, not a substitute.

A worked orientation example

To see how the bodies fit together on one product, take a mains-powered Wi-Fi and BLE connected sensor sold in both the EU and the US. The team has to satisfy three frameworks at once, and each one calls on a different combination of bodies, all resting on the same underlying laboratory work.

Framework	Who tests	Who decides / authorises	Accreditation behind it
EU EMC and safety (self-declared)	ISO/IEC 17025 lab	the manufacturer (DoC)	17025 lab accredited by an EA / ILAC member
EU radio with a partial standard	17025 lab	a Notified Body (EU-type certificate)	NB accredited 17065 / 17020, lab 17025
US radio (intentional radiator)	FCC-recognised 17025 lab	a TCB (FCC grant, FCC ID)	TCB accredited 17065, lab 17025
US safety (workplace)	NRTL	the NRTL (listing, UL/ETL mark)	OSHA recognition over 17025 / 17065

Read across the rows and the structure becomes obvious. The measurement is always a 17025 activity, and a single well-scoped lab campaign can feed every row: the radiated-emissions, conducted-emissions, RF and safety data are reused. What changes is the decision layer: the manufacturer itself for the self-declared rows, a Notified Body for the EU partial-standard radio route, a TCB for the US radio grant, an NRTL for the US listing.

Two practical lessons fall out of this. First, sequence the work so the accredited measurements come once and serve all four frameworks, rather than re-testing per market. Second, confirm early that each decision-making body accepts the lab you used: a TCB and an NRTL each have their own recognition lists, and a report from a lab outside those lists, however well accredited for CE, may not be usable for the US grant or listing. The accreditation is portable in principle through ILAC and IAF, but each recognition framework still publishes who it will accept.

This is exactly why getting the ecosystem clear first pays off: you can plan one test campaign and four decisions, instead of discovering mid-project that the body you need will not take the data you have.

How this differs from neighbouring topics

To keep the boundaries clear:

This page is about the bodies and the accreditation system, who measures, who certifies, who recognises whom.
Choosing which conformity assessment module (A, B, C, D, H) applies to your product is a separate decision, covered in modular conformity assessment under Decision 768/2008.
Choosing which specific Notified Body to engage, and reading NANDO scopes, is covered in notified body selection.
The whole framework sits under the EU CE system; the CE pillar is the entry point for the directives themselves.

Get the ecosystem right first, and the module choice and body selection that follow become much easier: you will know exactly what kind of body each task needs, and what an accredited report from it is worth.