ISO 17025 accreditation in the UK: the UKAS route, reference materials and the cycle after the grant

Why UK laboratories pursue ISO/IEC 17025 accreditation

UK laboratories seek UKAS ISO 17025 accreditation because the people who rely on their numbers ask for it: a manufacturer whose customers audit its measurement chain, another accredited laboratory that must show where its calibrations come from, a public body that accepts only results from a recognised scope, and export customers who want a report they need not re-test. The question they ask is narrow: is this test, on this range, on your UKAS schedule?

Public buyers are a second route. Since 24 February 2025 new rules under the Procurement Act 2023 govern public procurement, and the government's guidance on conditions of participation says a condition cannot require particular qualifications without allowing for their equivalents. Accreditation then becomes the easiest way to prove competence, and a laboratory without it must argue equivalence in every bid.

Accreditation stays voluntary in many sectors; the decision guide helps you test the case.

UKAS and the route to ISO/IEC 17025 accreditation

UKAS describes itself as the national accreditation body for the United Kingdom, appointed by government to assess organisations that provide certification, testing, inspection and calibration services, with its authority coming from the Secretary of State for Business and Trade. A "17025 certificate" issued by anyone else is not UKAS accreditation and appears on no UKAS schedule.

The UKAS route follows the pattern set out in our accreditation process guide, with its own markers. You submit an application form with the application fee. An optional pre-assessment, which UKAS calls an informal visit before initial assessment to determine how ready you are. The initial assessment is led by a Lead Assessor supported by Technical Assessors, who review records and witness key activities, so the staff named against each method must be able to perform it in front of them. Evidence against mandatory findings is due within about 12 weeks. On grant you receive a certificate and a public schedule of accreditation carrying an issue number and date.

On international recognition, UKAS states that it signs the European co-operation for Accreditation agreement and that its accreditations remain recognised under the Global ACI arrangement, which replaced the ILAC and IAF arrangements from 1 January 2026. The Global ACI list of recognised bodies, as viewed in September 2026, did not show UKAS, so confirm the position on both sites before an overseas contract relies on it. The guide to choosing an accreditation body explains what recognition guarantees.

Local practice that changes the project

Reference materials and suppliers

UKAS guidance TPS 57 on the selection and use of reference materials says a material from a producer accredited to ISO 17034 by a recognised body gives confidence in the producer's statements, and that the laboratory must be able to demonstrate the basis of its confidence to UKAS. Build supplier records for reference materials, calibration and proficiency testing around that expectation.

Flexible scopes

UKAS schedules can carry a flexible scope provision under UKAS GEN 4. If your methods change often, decide at application whether to seek one; the scope of accreditation guide covers the trade-offs, and UKAS sets the terms.

Mixed laboratories

Medical laboratories apply to ISO 15189, and inspection work falls under ISO/IEC 17020, whose 2026 edition UKAS will require for new applications from 1 January 2027. One management system can serve all three, but each needs its own scope.

The cycle after the grant

The first surveillance visit comes six months after the grant, then annual surveillance and full reassessment every fourth year.

UK items to check, and where

How Sterling works in the United Kingdom

For ISO/IEC 17025 accreditation in London and across the UK, Sterling supports laboratories from its London office, on site and remotely. Our expert and experienced laboratory accreditation consultants bring 8,100+ client engagements in 60+ countries since 2003. Sterling does not accredit: UKAS assesses your laboratory and makes the decision.

ISO/IEC 17025 in the UK: questions laboratories ask