UKAS and ISO 15189 Accreditation: A Biomedical Scientists Guide
Every result that leaves an NHS pathology laboratory is underpinned by a single quality framework: accreditation to ISO 15189:2022, granted by the United Kingdom Accreditation Service (UKAS). For biomedical scientists (BMS), accreditation is not an abstract management concern but a daily responsibility — it shapes how you document competence, record quality control, investigate errors and authorise results. This guide explains the current standard, how the UKAS assessment cycle works, the practical part you play in maintaining accreditation, and the non-conformities that most often trip laboratories up.
What ISO 15189 Is and Why It Matters
ISO 15189 is the international standard that specifies the requirements for quality and competence in medical laboratories. It is the benchmark against which UK pathology services demonstrate that their results are reliable, traceable and clinically safe. Unlike a generic quality standard, ISO 15189 is written specifically for laboratories that produce results used in patient care, so it covers the whole testing pathway — from how a sample is requested and collected, through examination, to how the result is reported and interpreted.
The current edition is ISO 15189:2022, published in December 2022. It replaced ISO 15189:2012 and, importantly, absorbed the requirements for point-of-care testing (POCT) that were previously contained in the separate standard ISO 22870:2016. This means a single accreditation now covers both the central laboratory and any laboratory-supported POCT services, such as blood gas analysers on a ward or HbA1c devices in a diabetes clinic.
UKAS-published transition arrangements required laboratories to move from the 2012 to the 2022 edition by 6 December 2025; from that date, services that had not transitioned faced suspension of their existing accreditation. By 2026, ISO 15189:2022 is the only edition under which UK medical laboratories operate.
UKAS: The UK's National Accreditation Body
UKAS is the sole national accreditation body recognised by the UK government for assessing organisations that provide certification, testing, inspection and calibration services. For pathology, this means UKAS is the only body that can accredit a medical laboratory to ISO 15189:2022. Accreditation by UKAS is a statement of competence: it confirms that an independent, technically expert assessment team has examined the laboratory and judged it to meet the standard.
It is important to distinguish accreditation from related but separate forms of oversight:
- UKAS accreditation (ISO 15189:2022) — confirms the laboratory's technical competence and quality management system.
- MHRA regulation — the Medicines and Healthcare products Regulatory Agency enforces the Blood Safety and Quality Regulations 2005. Blood establishments are authorised by the MHRA, while hospital blood banks are not formally licensed but must submit an annual Blood Compliance Report and may be inspected on a risk-based or for-cause basis. The MHRA also provides guidance on the validation and off-label use of in vitro diagnostic (IVD) devices. A transfusion laboratory will therefore typically hold UKAS accreditation and be subject to MHRA oversight.
- IBMS Laboratory Training Approval — the Institute of Biomedical Science separately approves laboratories to deliver pre-registration, support-staff and post-registration training. IBMS approval is distinct from UKAS accreditation because no other body checks that the training infrastructure required for IBMS qualifications and HCPC registration is in place.
The Clause Structure of ISO 15189:2022
A major change in the 2022 edition is its reorganisation to align with the ISO 17000-series "parent" standards, particularly ISO/IEC 17025:2017. The result is a logical, risk-based structure where management requirements sit at the end. Understanding the headline clauses helps you locate where your own work fits.
| Clause | Title | What it covers | |--------|-------|----------------| | Clause 4 | General requirements | Impartiality, confidentiality, and patient-related requirements (patients placed at the centre of laboratory activity) | | Clause 5 | Structural and governance requirements | Legal identity, the laboratory director's accountability, organisational structure, objectives and policies | | Clause 6 | Resource requirements | Personnel and competence, facilities and environment, equipment, reagents and consumables, and externally provided services | | Clause 7 | Process requirements | Pre-examination, examination and post-examination processes, including measurement uncertainty, reporting, and management of non-conformities | | Clause 8 | Management system requirements | Documents and records, actions to address risk and opportunity, audits, corrective action, continual improvement and management review |
Two themes run through the whole standard and represent the biggest shift from 2012:
1. Risk-based thinking. Laboratories must identify and act on risks to patient safety across every process, not just respond to errors after they occur. Risk management is woven through the standard rather than confined to one clause. 2. Reduced prescriptiveness. The 2022 edition uses more qualifiers such as "as appropriate", giving laboratories flexibility to justify what is suitable for their local service — and to explain, with evidence, where a requirement does not apply.
The UKAS Assessment Cycle
UKAS assesses laboratories over a rolling four-year cycle. Rather than a single pass-or-fail inspection, accreditation is maintained through continuous scrutiny. The typical journey is:
1. Application and gap analysis. The laboratory applies to UKAS, submits documentation describing its scope, policies and legal status, and may undergo an optional pre-assessment to identify significant gaps before the formal visit. 2. Initial assessment. A team led by a UKAS Assessment Manager and supported by technical assessors (often practising senior scientists and pathologists) examines the quality management system and witnesses testing across the requested scope. 3. Granting of accreditation. Once any findings are satisfactorily addressed and reviewed by an independent UKAS decision-maker, accreditation is granted against a defined scope listed on the laboratory's schedule. 4. Annual surveillance visits. Each year UKAS returns to confirm that the laboratory continues to meet ISO 15189:2022, sampling different parts of the system and scope over time. 5. Reassessment. A full reassessment of the entire scope is carried out, typically every four years, to renew accreditation for the next cycle.
Extensions to scope — for example adding a new test or discipline — can be assessed alongside surveillance visits or as standalone activities.
The Biomedical Scientist's Role in Maintaining Accreditation
Accreditation is not owned by the quality manager alone; it is sustained by the everyday practice of the whole laboratory team. As a BMS, you generate much of the evidence an assessor will examine. Your contribution typically includes:
- Working to current SOPs. Following the authorised version of each standard operating procedure and flagging documents that are out of date or unclear, so that document control (Clause 8) is demonstrably effective.
- Maintaining competence records. Completing initial training, ongoing competency assessments and continuing professional development, and ensuring these are signed off and retained. Competence underpins Clause 6.
- Running and reviewing quality control. Performing internal quality control (IQC), acting on out-of-control results, and participating in external quality assessment (EQA) schemes such as those run by UK NEQAS. Reviewing EQA returns and investigating poor performance is direct evidence for Clause 7.
- Documenting equipment and reagent checks. Recording maintenance, calibration, temperature monitoring and reagent lot verification so that traceability is intact.
- Raising and investigating non-conformities. Reporting incidents and errors honestly, contributing to root cause analysis (RCA) and helping implement corrective and preventive action (CAPA) — a core part of the risk-based ethos.
- Engaging during assessment. Being able to explain what you do, why you do it and where it is documented when an assessor observes your bench. Assessors frequently ask front-line staff to walk through a procedure from memory and then show the matching record.
Common Non-Conformities and How to Avoid Them
When a laboratory falls short of the standard, UKAS raises findings that must be resolved. Findings are generally categorised by severity, with the most serious requiring urgent action and capable, if uncorrected, of leading to suspension. Mandatory findings are typically given a defined deadline — commonly around one month — to submit evidence of corrective action, supported by root cause analysis rather than a quick fix.
Recurring areas of non-conformity reported during ISO 15189:2022 assessments include:
- Clinical risk not reflected in non-conformity records (Clause 7.5). Logging an error without documenting its potential impact on the patient. The risk-based standard expects each non-conformity to consider clinical risk and patient impact.
- Untested continuity and emergency plans (Clause 7.8). Having a business continuity or contingency plan on paper but no evidence it has been periodically tested or rehearsed.
- Audit schedules that are not risk-based (Clause 8). Auditing on a fixed rota without prioritising areas of higher risk, recent change or previous non-conformity.
- Document control gaps. Staff working from superseded SOPs, uncontrolled copies in circulation, or review dates that have lapsed.
- Incomplete competency evidence. Training delivered but not formally assessed, or competency assessments that are overdue.
- Weak corrective action. Closing a finding by "retraining the individual" without analysing the underlying system cause, so the same error recurs.
Frequently Asked Questions
Is ISO 15189 mandatory for NHS pathology laboratories?
There is no single statute that names ISO 15189 as a legal requirement, but in practice UKAS accreditation to ISO 15189:2022 is the expected standard for NHS pathology services and is required by commissioners, screening programmes and many service-level agreements. Operating without it would make a laboratory an outlier and could jeopardise its ability to deliver clinical services.
What is the difference between ISO 15189:2012 and ISO 15189:2022?
The 2022 edition restructured the standard to align with ISO/IEC 17025:2017, made risk-based thinking and patient focus central, became less prescriptive, and integrated point-of-care testing requirements previously held in ISO 22870:2016. UK laboratories were required to transition by 6 December 2025, so 2022 is the only current edition.
How often does UKAS visit an accredited laboratory?
UKAS works on a four-year cycle comprising an initial assessment, annual surveillance visits in the intervening years, and a full reassessment at the end of the cycle. Additional visits may occur for extensions to scope or to follow up on significant findings.
Does UKAS accreditation cover blood transfusion and point-of-care testing?
Yes. POCT is now covered within ISO 15189:2022, so laboratory-supported POCT services are accredited under the same standard rather than the withdrawn ISO 22870. Transfusion laboratories are accredited by UKAS while also being subject to MHRA regulation under the Blood Safety and Quality Regulations.
What happens if my laboratory receives a major non-conformity?
A serious finding must be addressed urgently with corrective action supported by root cause analysis, and evidence submitted to UKAS within the agreed timescale — often around one month. Until satisfactorily resolved, a major non-conformity can place accreditation at risk of suspension or, in extreme cases, withdrawal.
How is UKAS accreditation different from IBMS Laboratory Training Approval?
UKAS accreditation confirms the laboratory's technical competence and quality system under ISO 15189:2022. IBMS Laboratory Training Approval is a separate process confirming that a department can deliver IBMS qualifications — such as the Registration Training Portfolio leading to HCPC registration — and no other accreditation body performs those training-specific checks.
Further training
Continue building your quality and laboratory practice knowledge through our NHS Laboratory Training hub and these related guides: