ISO/IEC 17025 Accreditation · 8 min read
ISO/IEC 17025 Accreditation, Decoded
ISO/IEC 17025 is the standard that separates a competent calibration laboratory from a company that owns some equipment. This hub explains what accreditation proves, what it does not, and how to use it when you choose a lab — with focused articles on scopes, the 9001 comparison, and the buyer checklist beneath it.
What accreditation actually certifies
ISO/IEC 17025 is the international standard for the competence of testing and calibration laboratories. Accreditation to it means an independent accreditation body — in the US commonly A2LA — has assessed the lab against the standard: its technical methods, its staff competence, its equipment and traceability, and crucially its ability to estimate and report measurement uncertainty. That assessment is repeated on a cycle, not granted once and forgotten.
The distinction that matters to a buyer: ISO 9001 certifies that a company follows its own quality processes. ISO/IEC 17025 certifies that a lab produces technically valid measurement results. For calibration, only the second one answers the question you actually care about.
Accreditation is scoped — check the scope
A lab is not simply "17025 accredited" in the abstract; it is accredited for specific measurements over specific ranges with specific capabilities. That is the scope of accreditation, and it is a public document. A calibration is only accredited if the specific measurement falls within the lab’s scope — so a lab can be accredited yet perform a given calibration outside its scope (which then is not an accredited result).
American Gage holds A2LA accreditation under certificate 4296.01; the scope is published in the A2LA directory and linked from our accreditations page.
How to use this in supplier selection
When your customers or primes require accredited calibration, verifying a supplier is straightforward: confirm the accreditation is current with the accreditation body directly, and confirm the measurements you need are on the scope. The articles below walk through reading a scope, the 9001 vs 17025 difference, and a full lab-selection checklist.
In this guide
Common questions
Is ISO 9001 enough for a calibration supplier?
Usually not, when the calibration supports regulated product. ISO 9001 shows a company follows its processes; ISO/IEC 17025 shows a lab produces technically valid, uncertainty-quantified results. Many aerospace and medical customers require 17025 accreditation explicitly.
How do I verify a lab is really accredited?
Check the accreditation body’s public directory (e.g., A2LA) for the certificate and, importantly, the scope of accreditation. Confirm the specific measurements and ranges you need are listed.