Last Updated on September 25, 2025 by Melissa Lazaro

What is ISO/IEC 17043:2023? Definition & Scope Explained

If you work in laboratory accreditation, quality assurance, or manage interlaboratory comparisons, you’ve probably encountered the term ISO/IEC 17043. And with the 2023 update now in full effect, you might be wondering what’s changed and whether this standard applies to your organization.

Here’s the reality: ISO/IEC 17043:2023 isn’t just for elite testing bodies or national labs. It’s a practical, globally recognized framework for proficiency testing (PT) providers—one that helps ensure that labs are actually doing what they claim to do: producing valid, reliable test results.

As someone who has supported both small regional PT providers and large multinational organizations through this standard, I’ve seen how a solid understanding of ISO/IEC 17043 can transform both trust and technical rigor. In this article, we’ll break down what the standard means, who it’s for, what’s new in the 2023 revision, and how you can start preparing—whether you’re considering accreditation or simply want to do things right.

What ISO/IEC 17043:2023 Really Means—A Clear, Working Definition

Let’s begin with the most important question: what is ISO/IEC 17043?

ISO/IEC 17043:2023 is the international standard for the competence of proficiency testing providers. In simpler terms, it sets out how organizations that offer interlaboratory comparisons must operate to ensure that the results they generate are fair, technically sound, and useful for participants.

The standard ensures that the PT provider is not just distributing samples and collecting data, but managing the entire process responsibly—from planning and logistics to statistical evaluation and post-scheme reviews.

This matters because laboratories use PT schemes to assess their technical capabilities. If the PT provider isn’t competent, then the entire purpose of the comparison is compromised. ISO/IEC 17043 provides a framework that says, “Yes, this provider knows what they’re doing. Their schemes can be trusted.”

One of my clients, a national PT provider for agricultural labs, saw this firsthand. Before aligning with ISO/IEC 17043, their schemes were loosely structured. After implementation, their feedback scores improved significantly, and they were finally recognized by international accreditation bodies. That recognition brought them into regional trade networks they couldn’t previously access.

Scope of the Standard—What It Covers and Who It Applies To

ISO/IEC 17043 applies to any organization that offers or facilitates proficiency testing schemes. These schemes are a specific kind of interlaboratory comparison—where multiple labs perform the same test on identical items, and their results are compared to evaluate accuracy and consistency.

The standard applies regardless of the type of testing involved. Whether you’re offering PT in environmental chemistry, medical diagnostics, mechanical calibration, or microbiological analysis, the scope of ISO/IEC 17043 is broad. It applies to:

• Government-run PT programs
• Commercial proficiency testing providers
• Internal corporate PT schemes intended to evaluate multiple labs across regions
• Any organization offering PT to support ISO/IEC 17025 compliance

What does it cover? Quite a lot. The standard addresses:

• Planning and designing PT schemes
• Handling and distribution of test items
• Statistical evaluation of participant performance
• Ensuring impartiality and confidentiality throughout
• Reviewing scheme effectiveness and implementing improvements

For example, I once worked with a food testing PT provider expanding from local to international markets. They assumed ISO/IEC 17043 was out of scope because their participants were limited to one country. But once they understood that the size of the provider doesn’t matter—only the nature of the activity—they committed to implementation. Their compliance later helped them win contracts with ISO/IEC 17025-accredited labs that required ISO/IEC 17043-compliant PT.

Key Changes in ISO/IEC 17043:2023—What’s New and Why It Matters

The 2023 revision isn’t just a routine update. It introduces significant enhancements that reflect how the PT landscape has evolved.

Here are the most important updates:

• Alignment with ISO/IEC 17025:2017: Terminology and structure now closely reflect ISO/IEC 17025, making it easier for labs and PT providers to manage both systems in parallel.
• Risk-based thinking: PT providers are now expected to identify, assess, and manage risks to impartiality, quality, and confidentiality. This shift moves the standard away from rigid checklists and toward intelligent decision-making.
• Enhanced confidentiality requirements: Providers must implement systems to ensure that participant identities and data remain confidential—not just in theory, but in practice.
• Scheme effectiveness evaluation: The new version strengthens the requirement to evaluate how well a PT scheme achieved its objectives, including participant satisfaction, logistical performance, and result clarity.
• Defined responsibilities: The revision places more explicit expectations on top management, including the delegation of authority and oversight of impartiality.

I supported a provider during their transition who had historically stored participant data in unlocked spreadsheets with shared staff access. Under the new version, this was considered a serious risk. They implemented secure databases, role-based access controls, and documented their processes in a risk register. Not only did they pass their audit, but they also gained internal trust that their systems were robust.

How ISO/IEC 17043 Connects with ISO/IEC 17025 and ILAC Guidelines

If you operate an ISO/IEC 17025-accredited lab, or if you serve labs that are, the relationship between ISO/IEC 17043 and ISO/IEC 17025 is crucial.

ISO/IEC 17025 requires labs to participate in proficiency testing as part of their quality assurance. However, using a non-compliant PT provider can create major problems, especially during accreditation or surveillance audits. Accreditation bodies often expect those PT providers to follow ISO/IEC 17043—even if the lab itself isn’t directly responsible for that provider’s operations.

ILAC—the International Laboratory Accreditation Cooperation—strongly supports ISO/IEC 17043 as the benchmark for PT provider competence. So, even if you’re “just a participant,” knowing whether your PT provider meets this standard is in your best interest.

One of my clients, a calibration lab in Eastern Europe, unknowingly relied on a provider that wasn’t 17043-compliant. Their surveillance audit flagged this as a nonconformity, and they were forced to re-participate in alternate schemes within a tight deadline. It was expensive and stressful—and completely avoidable.

How to Prepare for ISO/IEC 17043:2023 Implementation

Whether you’re planning for accreditation or simply want to align with best practices, implementing ISO/IEC 17043 can seem daunting. But it doesn’t have to be overwhelming if you break it down.

Start with a gap analysis. Review your current operations clause-by-clause against the standard. This helps you identify which areas are already compliant and where improvements are needed.

Next, focus on building the following:

• Process-based documentation: Create clear SOPs for scheme planning, participant communication, result evaluation, and handling of complaints or disputes.
• Impartiality and confidentiality controls: Assign specific roles and safeguards. This might include confidentiality agreements, independent scheme reviewers, or IT-based data protection.
• Training for your team: Ensure that staff understand both the technical and ethical responsibilities tied to their roles. Scheme coordinators, statisticians, and support staff all need tailored guidance.
• Feedback and review systems: Implement structured mechanisms to evaluate the effectiveness of each PT round. Record what worked, what didn’t, and how you’ll improve future schemes.
• Management review and internal audits: These aren’t just formalities. They help you catch weak points, stay proactive, and demonstrate compliance during accreditation.

In my work with a mid-size provider in Southeast Asia, we rolled out a phased approach over nine months. They began with internal training, followed by developing scheme design SOPs, a pilot run, and eventually a full system audit. Their accreditation went smoothly—and their clients appreciated the improved transparency.

The Business Case—Why ISO/IEC 17043 Accreditation Pays Off

Implementing ISO/IEC 17043 isn’t just about meeting requirements. It’s about building trust, expanding your reach, and future-proofing your organization.

When you operate under a recognized standard:

• You gain credibility with regulators, labs, and accreditation bodies.
• You become eligible for international collaboration, including recognition by ILAC MRA signatories.
• You improve internal systems, reducing errors and increasing transparency.
• You offer more value to participants, who trust that their data is being fairly evaluated and protected.

One commercial provider I worked with saw a 30% increase in participation in the year following accreditation. Why? Because clients—especially ISO/IEC 17025 labs—need to prove their PT results are valid. Accreditation signals that your schemes are not only credible but reliable.

Pro Tips Based on Real Implementation Experience

Conduct a pilot scheme before going live
Running a pilot lets you evaluate your procedures, staff readiness, and systems under real conditions—without the pressure of external audits. Document everything: how you planned, how samples were distributed, how issues were handled, and what participant feedback revealed.

Create a risk register tailored to PT activities
Generic risk management won’t cut it. Develop a risk register that identifies specific PT-related risks, such as delayed sample shipments, scheme bias, or data breaches. Include mitigation plans and assign responsibility for each.

Secure your data properly
Confidentiality isn’t just about locking files—it’s about designing access systems, using secure communication platforms, and training staff to handle sensitive data properly. Make sure this is documented and demonstrable.

Tailor training to different roles
Not everyone needs the same level of training. Your scheme coordinators, analysts, and support staff have different responsibilities. Provide targeted sessions so they know exactly what’s expected of them.

Don’t copy ISO/IEC 17025 procedures directly
It’s tempting to use what you already have, but PT activities are different from lab testing. For example, your evaluation criteria, feedback loops, and communication models must reflect the specific requirements of ISO/IEC 17043.

Common Mistakes and Frequently Asked Questions

Common mistakes to watch out for:

• Treating ISO/IEC 17043 as a “documentation exercise” without cultural changes
• Failing to evaluate scheme effectiveness or collect participant feedback
• Assuming your lab-based quality system can be applied without modification
• Overlooking impartiality risks in scheme design and result interpretation

Frequently asked questions:

Is ISO/IEC 17043 mandatory?
No, but if you provide PT to ISO/IEC 17025-accredited labs or seek international recognition, it’s highly recommended—and often expected by accreditation bodies.

Is proficiency testing the same as interlaboratory comparison?
Not quite. PT is a specific type of interlaboratory comparison with defined evaluation criteria and structured feedback. All PTs are ILCs, but not all ILCs are PTs.

How long does implementation take?
It depends on the complexity of your operation and how much groundwork exists. Most providers complete implementation in six to twelve months when supported by internal commitment and external guidance.

Final Thoughts and Your Next Step

ISO/IEC 17043:2023 offers more than just a compliance checkbox. It provides a framework that helps proficiency testing providers deliver high-quality, trustworthy services that meet the needs of laboratories and regulators around the world.

It ensures that what you deliver isn’t just statistically sound—but ethically managed, clearly communicated, and consistently reliable. And when done well, it positions your organization as a leader in laboratory quality assurance.

If you’re ready to align with the new standard, start with a gap analysis and a plan. Don’t rush—build your system intentionally. If you’d like expert guidance, templates, or training resources, feel free to reach out. I’ve supported dozens of providers through this journey, and I’d be happy to help you navigate it confidently.

Let’s make quality real—not just certified.