A COA says "ISO 17025 lab": how to verify the accreditation and its scope

Why "third-party tested in an ISO 17025 lab" needs checking

Peptide vendors often cite independent testing and an ISO/IEC 17025 laboratory. Buyers ask how to confirm that claim. The answer is not to evaluate the vendor, but to verify the laboratory: who accredited it, whether the accreditation is current, and whether it covers the test that produced the number on your certificate.

This is a desk method using the International Laboratory Accreditation Cooperation (ILAC) and A2LA pages reviewed on 13 October 2026. Accreditation concerns a laboratory's competence for listed activities; it is not a certification of any product, lot or supplier.

Who accredits laboratories

ILAC explains that its Mutual Recognition Arrangement supports acceptance of calibration, testing and inspection results across borders. Signatory accreditation bodies are peer evaluated against ISO/IEC 17011 and accredit conformity assessment bodies, including calibration and testing laboratories assessed to ISO/IEC 17025. ILAC provides a signatory search, and many entries link to the accreditation body's own directory of accredited facilities, where laboratories can be found for specific tests or calibrations. [1]

A2LA, for example, describes itself as holding signatory status in the ILAC MRA, lists ISO/IEC 17025 for testing and calibration laboratories among its programs, and directs readers to its online directory for a current listing of accredited organizations. [2] Other countries have their own signatory bodies; use the ILAC search to find them. [1]

The four-step check

Work from the certificate, not the vendor's marketing page. The laboratory named on the report is the one that needs to be accredited for the reported test.

Scope is where most claims fail

An accreditation lists specific tests or calibrations. [1] A laboratory accredited for one technique or product type is not thereby accredited for every report it issues. Compare the test name, technique and, where shown, the matrix or material type in the scope with the method stated on your certificate. If the scope is ambiguous, write the exact scope wording into your record and ask the laboratory which scope line covers the reported test.

Also ask the laboratory, not the vendor, to confirm that the report number and lot exist. That step is described in this site's certificate guide, and it closes the gap between an accredited laboratory and a genuine report.

A fictional review

An invented certificate names "Example Analytical" and an accreditation certificate number. The signatory search confirms the named body is an ILAC MRA signatory. The body's directory lists Example Analytical with a current certificate, but its scope covers elemental analysis only, while the report gives an HPLC purity result.

The record reads: "Laboratory accredited by body B, certificate C, current on 13 October 2026; HPLC purity not found in scope; asked laboratory to identify covering scope line." The purity number is not declared false. Its accreditation support is unresolved.

Keep the conclusion narrow

A verified, in-scope accreditation supports confidence in a laboratory's competence for that activity. It does not establish that a particular sample was the lot you received, that the material is suitable for any use, or anything about safety. Record the check with dates so it can be repeated when the accreditation renews or the scope changes.