GHG Verification & Validation Process - Guardian Certification

The GHG Verification & Validation Process

How Guardian VB Works

Every GHG Verification and Validation engagement conducted by Guardian VB follows a structured, six-phase process governed by ISO 14064-3:2019 and ISO/IEC 17029:2019. This process is designed to ensure that every verification conclusion is based on sufficient, appropriate evidence; that all material misstatements are identified and resolved before a statement is issued; and that the final decision is made independently of the personnel who conducted the verification work. The process applies equally to Verification and Validation engagements, with activity-specific procedures applied at each phase.

The six phases — from initial scope definition through to formal statement issuance — are described below. Each phase has defined inputs, outputs, responsibilities, and controls. Guardian VB does not issue a Verification Statement until all phases are completed and the independent decision-maker is satisfied that the evidence supports the conclusion. No phase may be skipped or abbreviated without documented justification.

Clients are active participants in this process. Timely provision of GHG data, supporting documentation, facility access, and prompt responses to findings are essential to keeping engagements on schedule. Guardian VB will communicate openly with clients throughout each phase, but the verification conclusion remains the sole and independent judgement of Guardian VB.

The Six-Phase Verification Process

Phase	Name	Key Activities (Guardian VB)	Client Action Required
Phase 1	Pre-Engagement	Receive and review client's application for verification services Conduct scope feasibility assessment — standards, boundary, period, assurance level Screen all proposed team members for conflicts of interest (COI Declaration) Assess organisational and technical capability to undertake the engagement Communicate engagement acceptance or rejection with documented rationale	Submit application; respond to feasibility queries; disclose relevant relationships
Phase 2	Contract & Agreement	Prepare and issue formal Verification Agreement documenting scope, criteria, assurance level, timelines, fees and obligations Confirm client's GHG reporting boundary, reporting period, and applicable programme Document and retain signed Verification Agreement before any verification work commences Confirm outsourcing arrangements (if any) and obtain client consent	Review, sign and return the Verification Agreement; confirm scope and reporting boundary
Phase 3	Planning	Prepare the Verification Plan per ISO 14064-3 — scope, approach, sampling strategy, team roles Conduct Risk Assessment — inherent risk, control risk, detection risk per emission source Determine Materiality Threshold — quantitative and qualitative criteria Prepare Evidence Gathering Plan and Document Request List Assign verification team with confirmed competence and no COI	Provide Document Request List items promptly; confirm site visit logistics and access arrangements
Phase 4	Execution	Conduct document review — GHG inventory, supporting data, calculation methodologies Conduct site visit (on-site or remote/virtual) to verify data at source Perform data testing, recalculation, and cross-checking of emission calculations Evaluate GHG assertion against applicable criteria and materiality threshold Raise Findings (misstatements, non-conformities) and communicate to client for resolution Prepare Verification Report documenting work performed and conclusions reached	Provide full GHG data and records; facilitate site visit access; respond to findings within agreed timeframe
Phase 5	Technical Review	Assign an independent Technical Reviewer — a qualified person with no prior involvement in this engagement Technical Reviewer examines all working papers, evidence, findings, and draft conclusions Reviewer confirms that procedures were followed, evidence is sufficient, and conclusions are supported Reviewer identifies and resolves any significant findings before statement issuance Technical review documented and signed off before the decision stage	No client action at this phase — review is an internal Guardian VB quality control
Phase 6	Decision & Statement Issuance	Independent decision-maker (separate from verification team and technical reviewer) makes the final verification decision Decision-maker confirms that all requirements are met and the conclusion is supported GHG Verification Statement (or Validation Statement) prepared — including assurance level, scope, criteria, conclusion, and any emphasis of matter Statement reviewed for completeness and accuracy before issue Signed Verification Statement issued to client Engagement record retained per document control requirements	Receive and review the issued Verification Statement; confirm receipt in writing

Indicative Timelines

The following timelines are indicative only. Actual engagement duration depends on the complexity of the GHG inventory, the number of facilities, the level of assurance required, and the client's responsiveness during execution. Timelines are confirmed in the Verification Agreement prior to commencement.

Engagement Type	Indicative Duration	Notes
Single-site organisational inventory — Limited Assurance	3 – 4 weeks	Assumes complete documentation provided at planning stage and prompt finding resolution.
Single-site organisational inventory — Reasonable Assurance	4 – 6 weeks	Includes more extensive data testing and recalculation. Site visit typically required.
Multi-site organisational inventory — Limited or Reasonable Assurance	6 – 10 weeks	Duration increases with number of sites, emission sources, and Scope 3 categories included.
GHG Validation (project design document)	4 – 8 weeks	Dependent on programme requirements and completeness of the project design documentation.

Client Responsibilities

The quality and efficiency of a verification engagement depends significantly on client preparedness. Guardian VB requests that all clients fulfil the following responsibilities throughout the engagement:

Provide complete and accurate GHG data — including all Scope 1, 2 and 3 emission sources within the agreed boundary, supported by primary data records, meter readings, invoices, and calculation workbooks.
Provide supporting documentation — including organisational charts, facility lists, activity data logs, emission factor references, and methodology documentation as requested in the Document Request List.
Facilitate site visits — provide access to relevant facilities, operations, and responsible personnel for both on-site and remote (virtual) visits as required under the Verification Plan.
Respond promptly to findings — misstatements and non-conformities raised during execution must be addressed within the timeframe agreed in the Verification Agreement. Unresolved material misstatements will prevent statement issuance.
Accommodate observers — clients must make provisions, where applicable, for the presence of UAF accreditation assessors or trainee verifiers during any phase of the engagement, as required under ISO/IEC 17029.
Notify Guardian VB of material changes — any significant changes to the organisation's boundary, methodology, or data after planning but before statement issuance must be disclosed immediately.

Note:

Guardian VB conducts verification and validation solely as an independent third party. We do not provide guidance on how to prepare GHG inventories, select emission factors, or correct misstatements in a manner that could compromise our independence. Clients requiring GHG accounting support should engage a qualified GHG consultant separately, prior to engaging Guardian VB.