“Accreditation” and “certification” are often used interchangeably in casual conversation — but in the world of conformity assessment, they mean very different things, apply to different subjects, and carry different implications for trust and regulatory acceptance. Getting these terms right matters because using the wrong one in a proposal, on a website, or in a regulatory submission can create confusion or, in some cases, disqualify a bid.
The core distinction: accreditation is a formal recognition that a body (a laboratory, inspection body, or certification body) is competent to perform specific conformity assessment activities. Certification is a declaration — often by an accredited body — that a product, management system, or person conforms to specified requirements.
Accreditation: Recognizing Competent Bodies
Accreditation is granted by a national accreditation body (NAB) — organizations like A2LA, UKAS, DAkkS, or ANAB — after a rigorous, independent assessment. The accreditation body assesses the competence of the body being accredited to do what it claims to do.
Accreditation applies to three types of conformity assessment bodies:
- Testing and calibration laboratories — assessed against ISO/IEC 17025
- Inspection bodies — assessed against ISO/IEC 17020
- Certification bodies — assessed against ISO/IEC 17065 (product/service/process certification) or ISO/IEC 17021 (management system certification)
When a laboratory is accredited to ISO/IEC 17025, it means an independent body has verified that the lab’s technical competence, equipment, personnel, and management system meet the requirements of that standard for its defined scope. The accreditation does not certify a product, a process, or a person — it recognizes the lab itself as competent.
Accreditation is not permanent. It is subject to surveillance assessments and renewal. If the lab’s practices slip, the accreditation body can suspend or withdraw it.
Certification: Declaring Conformity
Certification is a third-party declaration that something — a product, a management system, or a person — meets defined requirements. Certification is typically issued by a certification body, which is itself often accredited (by an NAB) to do that certifying.
Management System Certification
ISO 9001 certification is the most widely recognized example. A certification body assesses an organization’s quality management system against the ISO 9001 standard and, if it meets the requirements, issues a certificate. The certificate says the system conforms — not that specific products or results are valid.
Laboratories sometimes hold both ISO 9001 certification and ISO/IEC 17025 accreditation. These overlap but don’t replace each other. ISO/IEC 17025 includes specific technical requirements for laboratory activities (measurement uncertainty, method validation, calibration traceability) that ISO 9001 does not address. Accreditation bodies typically require more than a 9001 certificate to grant laboratory accreditation.
Product Certification
Product certification (e.g., CE marking, UL listing, organic certification) is a declaration that a specific product or product type conforms to defined technical or regulatory requirements. The certification body testing and evaluating the product for that certificate is often itself accredited — to ISO/IEC 17065 — giving the market confidence that the certification body is competent to make that declaration.
Personnel Certification
ISO/IEC 17024 is the standard for bodies that certify individuals. A body accredited to ISO/IEC 17024 can certify persons against defined competency schemes — inspectors, auditors, practitioners, tradespeople, safety professionals, and many others.
This is where the terminology distinction becomes especially important: a laboratory accredited to ISO/IEC 17025 has not “certified” its personnel. The lab has authorized competent individuals to perform specific activities. If those individuals hold third-party certifications (e.g., a certified quality auditor credential), those come from a separate ISO/IEC 17024-accredited certification body.
The Trust Hierarchy
Understanding how accreditation and certification stack is useful when evaluating a supply chain, regulatory claim, or vendor qualification:
- National accreditation bodies (A2LA, UKAS, etc.) sit at the top. They accredit conformity assessment bodies against international standards. NABs themselves are peer-evaluated through international cooperation arrangements (ILAC for labs, IAF for certification bodies).
- Accredited conformity assessment bodies (labs, inspection bodies, certification bodies) operate in the middle layer. They have been assessed by the NAB and are authorized to conduct specific activities.
- Certificates, test reports, and inspection reports are the outputs that end customers and regulators receive. Their value depends on whether the issuing body is appropriately accredited.
This hierarchy explains why an accredited laboratory’s test report carries more regulatory weight than an unaccredited one: the data can be traced to an independently verified chain of competence assessments.
Common Confusions
“We’re ISO certified.” — This usually means the organization holds an ISO 9001 (or similar) management system certificate. It does not mean the organization is accredited, and it does not mean that its test or inspection results have been independently assessed for technical competence.
“Our lab is certified to ISO/IEC 17025.” — Technically imprecise. Laboratories are accredited to ISO/IEC 17025, not certified. This isn’t pedantry — accreditation and certification involve different processes, different assessors, and different levels of rigor on the technical side.
“Accreditation means our results are correct.” — Accreditation means the lab has demonstrated the competence, systems, and controls required to produce valid results under the standard. It does not guarantee any individual result is error-free, but it does mean there is a verified framework for detecting and correcting errors.
Why the Distinction Matters in Practice
In regulated industries, specifying “accredited laboratory” vs. “certified laboratory” in procurement documents, contracts, or regulatory guidance has real consequences:
- Environmental regulations frequently require test data from laboratories accredited to ISO/IEC 17025 by an NAB — a 9001-certified lab cannot substitute.
- Trade agreements that reference ILAC mutual recognition arrangements cover accredited laboratories, not just any organization with a quality certificate.
- Legal proceedings that rely on analytical results may scrutinize whether the laboratory was accredited, and for what scope.
If you are a laboratory seeking to understand which path applies to you, start with ISO/IEC 17025 for testing and calibration activities, ISO/IEC 17020 for inspection activities, and ISO/IEC 17024 if your organization certifies persons. Our free checklist can help you assess your readiness for the ISO/IEC 17025 accreditation path.
Note: Documentation templates and guidance materials support your accreditation preparation — they do not by themselves grant accreditation or certification. Formal recognition comes from your accreditation or certification body after a formal assessment.
Frequently Asked Questions
Can a company be both accredited and certified? Yes, and it is common. A testing laboratory might hold ISO/IEC 17025 accreditation (from an NAB) and also have its quality management system certified to ISO 9001 (from a certification body). These are complementary, not redundant — they assess different things.
Which is more rigorous: accreditation or certification? For laboratory activities, accreditation to ISO/IEC 17025 is more technically demanding than ISO 9001 certification because it includes specific requirements for measurement validity, traceability, and uncertainty that 9001 does not address. For management systems, certification to ISO 9001 and accreditation of a certification body to conduct 9001 audits are different activities entirely.
Do I need accreditation or certification to operate a laboratory? It depends on the jurisdiction and the intended use of the data. Some regulatory programs and procurement contracts specifically require accreditation. Others accept certification. Many do not require either, though accreditation typically signals higher credibility to customers and regulators.
Who accredits the accreditation bodies? National accreditation bodies are peer-evaluated by international cooperative bodies — primarily ILAC (International Laboratory Accreditation Cooperation) for testing and calibration labs, and IAF (International Accreditation Forum) for management system and product certification. Peer evaluation provides a second level of assurance that each NAB operates consistently with international standards.
Is ISO/IEC 17034 related to accreditation or certification? ISO/IEC 17034 is the standard for reference material producers — it applies to organizations that produce certified reference materials used in laboratory quality control and calibration. Reference material producers are accredited under this standard, and the certified reference materials they produce carry a different meaning of “certified” — it refers to the assigned values and their uncertainties, not a conformity declaration.