Last Updated on December 23, 2025 by Melissa Lazaro

What the ISO/IEC 17043:2023 Transition Really Means for PT Providers

If you’re responsible for a proficiency-testing program, the move from ISO/IEC 17043:2010 to the 2023 version probably feels familiar and unclear at the same time.

Familiar, because many core principles remain.
Unclear, because accreditation bodies are already applying 2023 thinking, even when formal transition timelines still sound generous.

In my work supporting PT providers through surveillance and transition assessments, the same question keeps coming up: “How much do we actually need to change?”

This guide answers that question clearly.

You’ll find a practical, step-by-step view of what the ISO/IEC 17043:2023 transition really involves, how assessors interpret it, and how to manage the change without disrupting your schemes or overloading your system.

Understanding the ISO/IEC 17043:2023 Transition – What Changed and What Didn’t

The 2023 revision is not a clean break from the 2010 edition. It’s an evolution.

What stayed the same:

• the core purpose of proficiency testing,
• the emphasis on technical validity,
• the need for impartiality and confidence in results.

What changed is how clearly you’re expected to explain and justify what you do.

ISO/IEC 17043:2023 strengthens alignment with other conformity-assessment standards and sharpens expectations around decision-making, risk, competence, and scheme design.

This matters because assessors no longer accept “we’ve always done it this way” as a sufficient explanation. They expect visible reasoning behind key choices.

A common misunderstanding is assuming unchanged clause numbers mean unchanged expectations. In practice, interpretation has shifted even where wording looks familiar.

When to Start the ISO/IEC 17043 Transition – Timing, Pressure Points, and Audit Reality

On paper, transition timelines can look comfortable. In real audits, they rarely feel that way.

Surveillance assessments don’t pause just because you’re transitioning. Assessors still evaluate how well your system aligns with current expectations—and those expectations increasingly reflect the 2023 version.

Waiting until a formal transition assessment to start work often creates unnecessary pressure. The most challenging findings I see usually come from late starts, not from lack of effort.

A more controlled approach is phased transition:

• start with understanding the changes,
• review higher-risk areas early,
• and build evidence progressively.

That approach gives you flexibility and credibility when assessors ask where you are in the transition.

Starting Point – Performing an ISO/IEC 17043 Transition Gap Review

Every successful transition begins with a clear picture of where you stand.

A transition gap review is not the same as a routine internal audit. Its purpose is to compare your current system—designed largely around 2010 expectations—against how ISO/IEC 17043:2023 is now interpreted.

A good gap review:

• identifies full compliance, partial alignment, and clear gaps,
• focuses on interpretation and effectiveness, not just documents,
• highlights areas that need redesign versus those that only need clarification.

One practical benefit of doing this early is control. You decide priorities, timelines, and resources—rather than reacting to audit findings.

Updating PT Schemes for ISO/IEC 17043:2023 Compliance

During transition, PT schemes move from the background to the center of attention.

Assessors sample schemes to understand how your system actually works in practice. Under ISO/IEC 17043:2023, they expect clearer alignment between:

• scheme objectives,
• scope and participants,
• design logic,
• statistical evaluation,
• and reporting.

Many existing schemes remain technically sound. What they often lack is explicit justification that connects all these elements together.

A common pitfall is treating scheme updates as document edits. In reality, they’re design reviews. The goal isn’t to change everything, but to ensure each scheme can be clearly explained and defended.

Risk-Based Thinking and Impartiality in the 2023 Transition

Risk and impartiality aren’t new concepts, but ISO/IEC 17043:2023 makes them more visible and more practical.

Risk is no longer something that sits quietly in a register. It’s expected to influence:

• scheme planning,
• decision-making,
• resource allocation,
• and review activities.

Impartiality is also examined more closely, especially where:

• subcontractors are involved,
• roles overlap,
• or key decisions rest with one person.

Assessors don’t expect complex frameworks. They expect realistic thinking and sensible controls that match the size and complexity of your operations.

Competence, Resources, and Subcontractor Control During Transition

Another noticeable shift in the 2023 version is how competence is assessed.

Qualifications and experience still matter, but they’re no longer enough on their own. Assessors want to see how competence is:

• defined for each role,
• evaluated over time,
• and supported when responsibilities change.

This applies equally to subcontractors. Using accredited laboratories or external experts doesn’t remove responsibility. You’re still accountable for how their work supports your PT schemes.

Clear role definitions and simple competence review records often work better than complex matrices that no one maintains.

Internal Audits During the ISO/IEC 17043 Transition

Internal audits play a quiet but powerful role during transition.

If audits continue to check only 2010-style compliance, assessors quickly notice the disconnect. At the same time, internal audits shouldn’t turn into speculative assessments of future requirements.

A balanced approach works best:

• continue auditing against current accreditation requirements,
• deliberately test selected 2023 expectations,
• and clearly document which criteria were used.

This shows awareness, learning, and control—three things assessors value highly during transition.

Managing the Transition Without Over-Engineering the System

One of the most consistent lessons from transition projects is that more change doesn’t always mean better outcomes.

Large-scale rewrites often introduce new risks:

• staff uncertainty,
• inconsistent implementation,
• and weak ownership.

In one transition project I supported, the PT provider chose a deliberately lean approach. Instead of rewriting everything, they focused on scheme justification, risk clarity, and competence evidence. The system remained familiar to staff, and the transition assessment resulted in no major findings.

That experience reinforced an important point: assessors value clarity and control far more than complexity.

Communicating the ISO/IEC 17043 Transition to Accreditation Bodies

How you talk about your transition matters almost as much as what you’ve implemented.

Assessors respond well to:

• clear explanations of your transition plan,
• honest acknowledgment of incomplete areas,
• and evidence of active management.

Trying to present the transition as “fully done” when it isn’t usually leads to deeper questioning. Transparency, paired with a structured plan, builds trust.

Using precise language helps. Explaining that certain areas are aligned with 2023 expectations while others are scheduled for update shows maturity, not weakness.

Common ISO/IEC 17043 Transition Mistakes and How to Avoid Them

Across transition projects, the same mistakes appear repeatedly:

• focusing on document updates instead of decision-making,
• leaving PT schemes untouched until late in the process,
• delaying transition work because deadlines seem far away,
• classifying transition gaps as full nonconformities.

Avoiding these issues doesn’t require more effort—just earlier focus and better prioritization.

FAQs – ISO/IEC 17043 Transition to the 2023 Version

Do PT providers need to be fully compliant with ISO/IEC 17043:2023 before transition audits?
No. Assessors expect progress, understanding, and control—not instant perfection.

Can small PT providers manage the ISO/IEC 17043 transition effectively?
Yes. Smaller systems often transition more smoothly when they stay focused and avoid over-engineering.

How long does a realistic ISO/IEC 17043 transition take?
It varies, but rushed transitions tend to create findings. Steady, phased approaches consistently perform better.

Conclusion – Managing the ISO/IEC 17043:2023 Transition with Confidence

The ISO/IEC 17043:2023 transition is not about doing more. It’s about being clearer.

Clearer about why your schemes are designed the way they are.
Clearer about how risks are managed.
Clearer about how competence is maintained.

PT providers who approach the transition deliberately—starting early, prioritizing wisely, and communicating openly—consistently experience smoother assessments and fewer surprises.

Handled well, the transition becomes less of an obligation and more of a strengthening exercise. And that’s exactly how accreditation bodies expect it to be managed.