By Dr Souha Bel Haj Messaoud | Founder, Eco Fluent Solutions Updated: July 2026 | Reading time: 11 min
Ask most validation and verification bodies (VVBs) whether their team is competent: the answer is always yes. Ask them to demonstrate it — criteria, assessment records, role-by-role qualification evidence — and the conversation changes quickly.
That is the ISO 14066 problem. Not that VVBs lack competent people, but that competence is assumed rather than defined, assessed and documented in a way that satisfies an accreditation assessor.
ISO 14066 is the standard that fixes this. For any VVB being built or operated, understanding it is not optional: it is one of the areas accreditation bodies examine most closely.
This guide explains what ISO 14066 actually requires, how it connects to your ISO 17029 accreditation, and practical steps to build a competence system that holds up under external scrutiny.
What is ISO 14066?
ISO 14066:2023 defines competence requirements for validation and verification teams in the field of greenhouse gases (GHG) and environmental information.
It applies to the people who perform validation and verification activities — not to the organisation as a whole, but to the individuals and teams doing the work.
In plain terms: ISO 14066 answers “what must a person know and be able to do before being authorised to validate or verify a GHG statement or environmental claim?”
It covers:
- types of competence required (technical, process, behavioural)
- roles within a team and what each role requires
- how to assess and document competence
- how to maintain and develop competence over time
ISO 14066 does not work in isolation. It is read with ISO 17029:2019 (general VVB framework), ISO 14065 (GHG body requirements) and ISO 14064-3 (verification engagement principles).
Why ISO 14066 matters for VVB accreditation
During an accreditation audit, three tests come back systematically:
- You have defined what competence means for each role.
- You have assessed your people against those criteria.
- You keep records that demonstrate it.
Without these three elements, even an experienced team can generate major nonconformities.
Three competence dimensions under ISO 14066
1. Technical competence
Knowledge of schemes (inventories, projects, claims), quantification methods, uncertainties, emission factors, sector standards and judgement on technical materiality.
2. Process competence
Mastery of ISO 14064-3 / ISO 17029 engagement steps: planning, sampling, evidence collection, review, conclusion and communication.
3. Behavioural competence
Integrity, impartiality, communication, conflict management, critical thinking and the ability to document professional judgement.
Roles covered by ISO 14066
Validators and verifiers
Perform the field work, collect and evaluate evidence, raise findings and contribute to the conclusion.
Technical reviewers
Independently examine the file, methodology and judgements — without having led the primary verification.
Team leaders
Coordinate the team and ensure methodological consistency and conformity with the body’s procedures.
Building a compliant competence system: four steps
Step 1: Define competence criteria by role and sector
Avoid vague criteria (“good GHG knowledge”). Specify schemes, levels, tools and expected evidence for each role.
Step 2: Assess each person against the criteria
Training, examination, witnessing, file review, structured interview — combine methods according to risk.
Step 3: Document and retain records
Assessment grid, date, assessor, authorisation decision, authorised scope, reassessment due date.
Step 4: Review, monitor and develop competence
Internal audits, accreditation feedback, new schemes (CSRD, 14019): update criteria and training plans.
Most frequent competence gaps in audit
- Criteria too generic or copied from another scheme without adaptation.
- CV used as evidence without documented assessment.
- No separation between technical and process competence.
- Technical reviewer qualification not documented separately.
- No reassessment calendar or gap-handling process.
ISO 14066 and ISO 17029: how they connect
ISO 17029 requires the body to manage competence systemically. ISO 14066 specifies what each person must demonstrate on GHG and environmental engagements. The accreditation body checks both: the system (17029) and role-level evidence (14066).
FAQ — ISO 14066
Does ISO 14066 apply to all VVBs or only carbon?
It targets teams working on GHG and environmental information; CSRD sustainability-assurance VVBs also rely on broadened competence expectations via ISO 17029 and assurance frameworks.
Can one person hold several roles?
Yes if the body demonstrates absence of conflict and documents competence for each role — independence of the final decision remains critical.
How often should competence be reassessed?
According to risk, audit feedback and scheme changes; define periodicity in an HR/competence procedure.
What counts as valid technical competence evidence?
Training + assessment + witnessing or file review — not a diploma alone.
What if someone does not meet the criteria?
Development plan, scope restriction, reassessment — never “implicit” authorisation.
Does ISO 14066:2023 change much versus the previous version?
It clarifies roles, competence dimensions and documentation expectations — assessors are stricter on demonstration than on declared experience.
Is your competence system ready for accreditation?
If you hesitate on any of the three tests (define, assess, record), treat competence before the audit — not the night before. It is often the highest-ROI lever to secure ISO 17029 / 14065 accreditation.
Support for verification bodies: explore our ISO 17029 & ISO 14065 support or contact us.
