Pre-assurance readiness checklist

Is the underlying subject matter and the subject matter information to be assured identified disclosure by disclosure, and agreed with the practitioner in writing, so the scope of the assurance conclusion is unambiguous?

Evidence: Agreed schedule of in-scope disclosures and KPIs; terms of engagement or scoping correspondence; draft report marked up to identify the assured information

Does each in-scope KPI have a documented measurement basis (metric definition, unit of measure, population, inclusions and exclusions) precise enough for the practitioner to evaluate the subject matter against it?

Evidence: Reporting criteria document with one entry per KPI: definition, unit, population, inclusions and exclusions

Are the applicable criteria identified for each KPI (GRI, IFRS S1 and S2, ESRS, the GHG Protocol or entity-developed criteria), and do they exhibit the characteristics of suitable criteria: relevance, completeness, reliability, neutrality and understandability?

Evidence: Criteria mapping per KPI citing framework, version and year; documented rationale for any departure from the framework

Where entity-developed criteria are used, are they made available to the intended users, typically in a published basis of preparation, so the criteria meet the availability precondition of ISAE 3000 (Revised)?

Evidence: Approved basis of preparation, scheduled for publication alongside the subject matter information

Is the organizational boundary defined, listing the entities consolidated and the consolidation approach (operational control, financial control or equity share), and is it reconciled to the reporting boundary disclosed in the report?

Evidence: Entity schedule reconciled to the legal group structure; consolidation approach stated consistently in the report and the methodology

Are the operational boundaries defined at site and activity level, and is the reporting boundary applied consistently across KPIs, with any KPI-specific limitation of coverage disclosed?

Evidence: Site register mapping each site to the KPIs it reports; disclosure of KPIs reported on a narrower boundary

Are acquisitions, divestments, openings and closures in the period identified, with the effective date each entered or left the reporting boundary and the treatment applied to its data?

Evidence: Structural change register with effective dates; treatment documented in the methodology and, for GHG, assessed against the base year recalculation policy

Is the reporting period consistent across the subject matter information, and are cut-off procedures documented for activity spanning the period end, such as utility billing cycles and fuel deliveries?

Evidence: Reporting period stated in the report; cut-off rule in the methodology; apportionment workings for invoices straddling the period end

Is the level of assurance, limited or reasonable, agreed per disclosure, and does it satisfy the requirement of the regulator, exchange or lender the assurance responds to?

Evidence: Terms of engagement stating the level of assurance per disclosure; the loan covenant, listing rule or regulatory requirement it addresses

Is the assurance standard governing the engagement agreed (ISAE 3000 (Revised), ISSA 5000 for periods beginning on or after 15 December 2026, ISO 14064-3 for a GHG statement, or AA1000AS v3), and is any combination, such as ISO 14064-3 for emissions within a wider ISAE 3000 or ISSA 5000 engagement, explicit?

Evidence: Standard or standards named in the terms of engagement; references to assurance in the report consistent with them

Is it determined whether comparative information falls within the scope of the assurance conclusion, and is unassured comparative information identified as such in the report?

Evidence: Scope note on comparative information; report tables distinguishing assured and unassured periods

Is there an audit trail for each KPI from source record to reported figure, covering source system, extraction, manual intervention, transformation, consolidation and the report table, that the practitioner can walk through end to end?

Evidence: Data flow narrative or lineage table per KPI naming the file or system at each step; walkthrough performed and documented

Are the source records supporting each KPI identified and retrievable for every site and month, so the practitioner can vouch reported amounts to underlying documentation?

Evidence: Source record inventory per KPI (invoices, meter readings, payroll extracts, incident logs); retrieval of a random selection performed and timed

Is the quantification methodology for each KPI documented, and does the calculation as performed conform to it with no undocumented overrides?

Evidence: Methodology document; formula review of calculation workbooks against it for a selection of KPIs

Are emission factors and conversion factors referenced to source, version and publication year, appropriate to the activity and geography, and applied consistently across sites and periods?

Evidence: Factor register citing database, version and year; no hard-coded factors in calculation workbooks

For each estimate (gap-filling for missing periods, unmetered sites, extrapolation from samples), are the method, the data and assumptions used and the estimate's share of the reported total documented, so the practitioner can evaluate estimation uncertainty?

Evidence: Estimates register with method, period, inputs and share of the KPI; disclosure in the report where estimation uncertainty is significant

Are the significant assumptions underlying each KPI documented with their rationale and approved, and has management considered whether a reasonable alternative assumption would change the reported figure materially?

Evidence: Assumptions log with rationale, approver, date and sensitivity note

Does the consolidation include controls over completeness (every in-boundary site reported), accuracy (no double counting, consistent units) and aggregation, with exceptions investigated and cleared?

Evidence: Consolidation workbook with a completeness check against the site register, unit conversion table and exception log

Can each reported figure be re-performed from source data by a person independent of the preparer, using only the documented criteria and methodology, and does the result agree?

Evidence: Re-performance of a selection of KPIs by an independent reviewer, with differences explained and cleared

Have period-on-period and site-on-site movements above a defined threshold been analysed, with explanations corroborated by evidence rather than by assertion, ahead of the practitioner's own analytical procedures?

Evidence: Variance analysis per KPI and site with threshold, explanation and corroborating document

Is the subject matter information in the draft report, including tables, charts and quantified narrative statements, agreed to the final data set, so no material inconsistency with other information arises?

Evidence: Tie-out of the draft report to the final data file, each assured figure referenced to its working paper

Where previously reported information has been restated, are the nature, cause and magnitude of the restatement disclosed, and is the restated figure supported to the same evidential standard as the current period?

Evidence: Restatement log; disclosure in the report; workings and source evidence for each restated figure

Is accountability for each KPI, and for each site's submission, assigned to a named owner within the internal control over sustainability information?

Evidence: Responsibility matrix by KPI and site

Have reporting entities been issued period-specific reporting instructions setting out the applicable criteria, templates, cut-off and submission deadlines?

Evidence: Group reporting manual or instructions with version and issue date; templates as completed by sites

Is each submission subject to a documented review by a person other than the preparer, with review evidence a practitioner could test for operating effectiveness?

Evidence: Reviewer identity, date and review comments per submission; queries raised and cleared

Is there an approval hierarchy from site to group, ending with management's formal approval of the final data set before it enters the report?

Evidence: Signed or system-recorded approvals at each level; management approval of the final data set

Have those charged with governance (board, audit committee or sustainability committee) reviewed the assurance scope and scheduled approval of the report before publication?

Evidence: Committee minutes or agenda recording the scope review and the approval date

Where data is sourced from ERP, HR, building management or ESG software, are IT general controls in place over access, change management and report extraction, so system-generated information can be relied on?

Evidence: User access listing; change log; saved query or standard report used for each extraction, with run date and parameters

Are calculation workbooks subject to end-user computing controls: version control, locked formulas, segregated inputs and a single identified final version?

Evidence: Protected workbooks; version history in the document library; one final file per KPI

Where information is obtained from landlords, contractors, waste carriers or suppliers, has its reliability been evaluated and corroborated against an independent record before use?

Evidence: Schedule of externally sourced data; corroboration to invoices, weighbridge tickets or contract records

Is management prepared to give written representations acknowledging its responsibility for the subject matter information, confirming that all relevant information has been provided and disclosing known misstatements and subsequent events, and is the signatory agreed?

Evidence: Draft representation letter reviewed by management; signatory named; schedule of known misstatements and subsequent events

Is the evidence file indexed by KPI and site, with each document cross-referenced to the figure it supports, so the practitioner can obtain sufficient appropriate evidence without repeated requests?

Evidence: Evidence index with cross-references; folder structure matching the index

Can a complete population listing be produced for each KPI (invoices, meters, incidents, employee records) and reconciled to the reported total, so the practitioner can select its own sample?

Evidence: Population listings reconciled to reported totals

Is each in-scope qualitative disclosure, such as a renewable electricity share, a certification held or a policy in force, supported by documentary evidence on file?

Evidence: Claims register cross-referenced to certificates, contracts and approved policies

Do the policies and procedures cited in the report exist, carry evidence of approval and an effective date, and agree in substance with how the report describes them?

Evidence: Approved, dated copies of each policy cited in the report

Have the findings, misstatements and recommendations from the prior-period assurance engagement been remediated, with evidence of remediation for each?

Evidence: Prior-period management letter or findings schedule with remediation evidence and closure dates

Are known misstatements, unresolved data gaps and events after the reporting period recorded, with their effect on the subject matter information assessed against materiality?

Evidence: Schedule of misstatements and subsequent events with assessed effect and treatment

Is the evidence retained in its original form, protected from subsequent alteration, for at least the period required by the practitioner and any regulator?

Evidence: Retention rule; read-only archive of the final data set and evidence file at sign-off

Is there a GHG statement prepared to ISO 14064-1 or the GHG Protocol Corporate Standard, stating the organizational and operational boundaries, reporting period, greenhouse gases covered and emission categories or scopes?

Evidence: GHG statement or inventory report; criteria named; gases listed

Are Scope 1, Scope 2 and the in-scope Scope 3 categories listed, with each exclusion justified on magnitude, relevance or data availability and its size estimated?

Evidence: Category screening with exclusion rationale and estimated magnitude

Is Scope 2 reported under both the location-based and the market-based method, with contractual instruments (energy attribute certificates, green tariffs) matched to the period, volume and sites claimed?

Evidence: Both Scope 2 totals; certificates or supplier statements reconciled to consumption

Are global warming potential values drawn from a single stated IPCC assessment report and applied consistently across the current period and the base year?

Evidence: GWP source stated in the methodology; identical values in the base year and current period

Are stationary and mobile combustion quantities supported by primary activity data (delivery notes, fuel card statements, generator logs) and reconciled to purchases?

Evidence: Activity data by site and month reconciled to invoices

Are fugitive refrigerant emissions quantified from recorded top-ups by equipment and gas type, sourced from maintenance contractor records, rather than inferred from charge capacity alone?

Evidence: Equipment register with charge sizes; contractor service logs recording gas added

Is the base year stated with a recalculation policy and significance threshold, and has the base year been recalculated for structural or methodological changes exceeding that threshold?

Evidence: Base year and recalculation policy in the methodology; recalculation workings where triggered

Has the materiality the verifier will apply, as recorded in the ISO 14064-3 verification plan, been discussed, and are emission sources ranked so those that could individually or in aggregate approach it are known?

Evidence: Materiality stated in the verification plan or terms of engagement; emission sources ranked by magnitude

Have the significant sources of quantification uncertainty been assessed and, where the applicable criteria require it, disclosed?

Evidence: Uncertainty assessment by source; disclosure in the GHG statement

Are removals and carbon credits reported separately from gross emissions, with registry retirement evidence for every credit applied?

Evidence: Gross and net figures shown separately; registry retirement statements

Has the practitioner confirmed compliance with independence requirements, and is it free of any self-review threat from preparing the data, compiling the inventory, designing the controls or drafting the report it will assure?

Evidence: Written independence confirmation; schedule of other services the practitioner provided in the period

Are the terms of engagement agreed in writing, covering the subject matter, applicable criteria, assurance standard, level of assurance, form of the assurance report and timetable?

Evidence: Signed engagement letter consistent with checks 1.1 to 1.10

Does the timetable work back from the publication date, with data freeze, fieldwork, draft assurance report and governance approval each dated?

Evidence: Agreed engagement timetable aligned with the board calendar and publication date

Are the sites selected for visits or remote testing agreed with the practitioner, with site contacts briefed and site records available for inspection?

Evidence: Site visit plan with dates and contacts; site evidence packs prepared

Has the practitioner's information request list been received and assigned, with a single coordinator tracking each request to delivery?

Evidence: Request tracker with owner, due date and status for each item

Will the practitioner receive the report in its final form before signing, so it can read the other information for material inconsistency with the assured subject matter information?

Evidence: Version control of the report; date the final draft is provided to the practitioner

Is the location of the assurance report agreed, and does the report identify clearly which disclosures fall within the assurance conclusion?

Evidence: Report layout showing the assurance report's position and the marker on assured disclosures