ISO/IEC 17043 sets the requirements a proficiency testing (PT) provider must meet to show it is competent, impartial and runs its schemes consistently. The current edition is ISO/IEC 17043:2023, published in May 2023, and the ILAC transition ended on 31 May 2026, so accreditation to the 2010 edition is no longer recognised under the international arrangement now run by Global ACI (formerly ILAC and IAF).
This guide is for organisations that run PT schemes and for laboratory quality managers who choose PT providers.
What does ISO/IEC 17043:2023 cover?
Proficiency testing checks how well a laboratory performs by comparing its results with other laboratories that tested the same or similar items. ISO/IEC 17043 does not apply to the laboratories taking part. It applies to the organisation that designs the scheme, produces and sends the PT items, evaluates the results and reports performance.
According to ISO's page for the standard, the 2023 text is the second edition. It runs to 36 pages, was prepared by ISO's Committee on Conformity Assessment (CASCO) and replaces ISO/IEC 17043:2010, which is withdrawn. ISO also says that scheme users, regulators, peer-assessment schemes and accreditation bodies can use it to confirm a provider's competence.
The requirements sit in five clauses. Clause 4 covers impartiality and confidentiality. Clause 5 covers the provider's legal and organisational structure.
Clause 6 covers resources: personnel, facilities and environmental conditions, and externally provided products and services. Clause 7 covers the PT process itself, and clause 8 covers the management system.
What changed from the 2010 edition?
The foreword of the 2023 edition lists the main changes. The structure and technical requirements were harmonised with ISO/IEC 17025:2017. Terminology was aligned with ISO 13528:2022, the standard on statistical methods for proficiency testing. Requirements from an ISO/CASCO procedure document were added.
Annexes A and B were revised and Annex C was deleted.
One change matters most in practice. Any testing, calibration or PT item production the provider carries out now has to meet the relevant requirements of the matching ISO conformity assessment standard. If you test your own items for homogeneity, that testing should meet the ISO/IEC 17025 (or ISO 15189) requirements on valid results.
The Standards Council of Canada, an accreditation body, summarised further changes in its 2023 transition bulletin. "Subcontractors" became "external providers", and participants must be told in writing about external providers whose work can affect the PT activities. Complaints and appeals now have separate clauses.
A new clause covers surveillance of the PT processes. When a PT item is produced as a reference material, the relevant ISO 17034 requirements apply.
Who accredits PT providers, and when did the transition end?
Accreditation bodies accredit PT providers, as they do testing laboratories. Most national accreditation bodies are signatories to the Global ACI arrangement (formerly the ILAC Arrangement) and work to ISO/IEC 17011. A PT provider is accredited, not certified. A certification body has no role here.
The ILAC General Assembly endorsed Resolution GA 26.09 in November 2022. It set a three-year implementation period, with the deadline at 31 May 2026, according to ILAC's announcement. After that date, accreditation to the 2010 edition is not recognised under the ILAC Arrangement. Individual accreditation bodies set their own schedules inside that window, so check your own body's dates and records.
What does an assessor look for in a PT round?
An accreditation assessment follows the scheme, not just the manual. The assessor usually picks a completed round and asks for the records that prove each step of clause 7 was carried out. The table pairs the clause 7 topics with the evidence a provider typically keeps. The evidence column is AGS's practical interpretation, not text from the standard.
| Clause 7 topic | What the provider has to get right | Typical evidence for one round |
|---|---|---|
| 7.1 Scheme objectives and contracts | Agreeing what each scheme offers and telling participants how it runs | Scheme description, participant registration, PT calendar, contract review records |
| 7.2 Design and planning | Statistical design and how assigned values are set | Scheme design plan, statistical design, assigned value report with its uncertainty |
| 7.3 Production and distribution of PT items | Items that are homogeneous and stable, then handled, packed and sent correctly | Production report, homogeneity and stability results, delivery and receipt notes, participant instructions |
| 7.4 Evaluation and reporting | Analysing data, scoring performance and issuing reports | Result sheets, data analysis, performance scores, the final PT report |
| 7.5 Control of the process | Technical records, data management, surveillance and nonconforming work | Raw data and calculations, data integrity checks, nonconforming work reports |
| 7.6 and 7.7 Complaints and appeals | Handling a participant's complaint or appeal against an evaluation | Complaint and appeal registers with outcomes |
Two areas need particular care because they are specific to PT. The first is homogeneity and stability. You need to show that every participant received an equivalent item and that it did not change before testing.
The second is the assigned value. You need to show how it was set and how its uncertainty was handled in the scoring.
A provider seeking first accreditation also needs at least one complete round run under its own system. Without one, there are no records for the assessor to trace.
How do laboratories use accredited PT schemes?
The demand for PT comes from the standards that laboratories are accredited to. ILAC's policy on proficiency testing, ILAC P9:01/2024, points to ISO/IEC 17025:2017 clause 7.7.2 and ISO 15189:2022 clause 7.3.7.3. Both expect a laboratory to compare its performance with other laboratories through PT, or through other interlaboratory comparisons where PT is not available or suitable.
The same policy says laboratories must plan their participation, based on risk, including the level and frequency of PT for each area. Medical laboratories call PT external quality assessment (EQA). Our ISO/IEC 17025 guide covers the testing laboratory side, and the ISO 15189 guide covers medical laboratories.
When you choose a provider, check three things. Is the scheme inside the provider's scope of accreditation to ISO/IEC 17043:2023? Does the scheme match your test methods, matrix and measuring range? Do the provider's reports give you enough to investigate a poor score?
Hospital laboratories working towards JCI should also read our guide to JCI laboratory accreditation.
How AGS can help
The ISO17043 Management System kit contains 110 editable Microsoft Word documents. It includes a quality manual, a PT scheme description and 25 procedures, among them scheme design, homogeneity and stability, assigned value and uncertainty, and evaluation and reporting. There are 62 forms, 8 compliance checklists, participant guidance and a clause-to-document matrix for ISO/IEC 17043:2023 clauses 4 to 8.
Frequently asked questions
Is ISO/IEC 17043:2010 still valid?
No. ISO lists the 2010 edition as withdrawn, and under ILAC Resolution GA 26.09 accreditation to it has not been recognised under the ILAC Arrangement since 31 May 2026.
Can a PT provider be ISO/IEC 17043 certified?
No. PT providers are accredited by accreditation bodies, in the same way as testing laboratories. Certification bodies certify management systems such as ISO 9001, which is a different activity.
Does ISO/IEC 17043 tell you which statistics to use?
It sets requirements for statistical design and evaluation and gives statistical methods in informative Annex B. ISO 13528:2022 gives detailed statistical methods, and the 2023 edition aligned its terms with it.
Does buying documentation mean a provider will be accredited?
No. Documents are a starting point. Accreditation depends on how the schemes are run and on the accreditation body's assessment.
AGS provides independent documentation toolkits. This guide and the referenced kit are not affiliated with, endorsed by or approved by ISO, IEC, ILAC or any accreditation body, and they do not guarantee any assessment or accreditation outcome.
Reviewed October 2026. Facts checked against the sources current at publication.
