GHG Protocol · Corporate greenhouse gas accounting and reporting
GHG Protocol inventory consulting for scope 1, 2 and 3 figures you can defend.
There is no GHG Protocol certificate: customers, investors and regulators rely on an inventory prepared in conformance with the GHG Protocol standards and, where they ask for it, verified by an independent, accredited verification body. Sterling's expert and experienced consultants set your boundaries, build the scope 1, 2 and 3 calculations and the evidence trail with your people, write the inventory report and stay with you through verification, in 60+ countries. We ensure successful verification for our clients.
- An all-inclusive proposal for an agreed scope: consulting, Effivity software, Sterling Academy access and internal auditor training, as applicable to your standard, set out in one proposal
- A team of expert and experienced carbon accounting consultants, advising on management systems across sectors and countries since 2003
- The Sterling Promise: 100% on-time completion, 100% success, 8,100+ client engagements. Sterling builds the inventory and the evidence; an accredited verification body verifies it where verification is required.
8,100+ client engagements in 60+ countries.
GHG Protocol client experience
What it is
What is the GHG Protocol and what is it used for?
The Greenhouse Gas Protocol is the set of accounting standards behind most corporate emissions figures. Built on a partnership between the World Resources Institute and the World Business Council for Sustainable Development, it tells a company how to draw its boundary, how to sort emissions into scope 1 (sources it owns or controls), scope 2 (the generation of the electricity, steam, heat and cooling it purchases) and scope 3 (all other indirect emissions, up and down the value chain), how to track them against a base year and what a report must disclose. The GHG Protocol reports that in 2023, 97% of the S&P 500 companies disclosing to CDP used it.
Behind every questionnaire answer, target and climate disclosure sits the same test: is the figure complete, and would it come out the same if someone else recalculated it from your records? The Corporate Standard's five principles, relevance, completeness, consistency, transparency and accuracy, are the conditions it has to meet.
Current editions and revision status, September 2026. The Corporate Accounting and Reporting Standard is in its revised edition of 2004, which replaced the first edition of September 2001. An amendment of February 2013 updated the required gases and global warming potential values, and the Scope 2 Guidance of January 2015 amended it for energy contracts. The Corporate Value Chain (Scope 3) Standard was released in 2011. All three are under revision. The public consultation on Scope 2 ran from 20 October 2025 to 31 January 2026, and its results were published on 29 July 2026. The same day, the GHG Protocol and ISO announced that the Corporate Standard, Scope 2, Scope 3 and the Actions and Market Instruments work will be combined with ISO 14064-1 into one joint corporate standard, with a consolidated public consultation planned for Q2 2027 and publication for Q4 2028, subject to confirmation by the two organisations. The feedback summary on Actions and Market Instruments followed on 23 September 2026. Until the joint standard is published, your inventory is prepared against the current editions. GHG Protocol revision: what is changing and when
Who it is for
Who needs a GHG Protocol inventory?
Any organisation whose emissions are about to be read by someone outside it: manufacturers and their suppliers, logistics and construction firms, banks, technology and BPO groups, hospitals and public bodies. The request usually arrives from one of four directions:
- A customer or investor asks for scope 1, 2 and 3. Supplier questionnaires are written in GHG Protocol terms, and CDP aligns its climate reporting requirements with the Corporate Standard, the Scope 2 Guidance and the Scope 3 Standard. Agree the reporting year, boundary and categories expected before the first data request goes out.
- A disclosure rule turns the method into a compliance question. IFRS S2, the ISSB's climate standard, requires scope 1, 2 and 3 emissions to be measured in accordance with the 2004 Corporate Standard; amendments issued in December 2025, for periods beginning on or after 1 January 2027, ease some of those requirements. Companies still within the EU's CSRD, which the 2026 Omnibus directive narrowed to the largest companies, report material climate matters under ESRS E1.
- A target or a claim needs a base year. The SBTi's Corporate Net-Zero Standard V2.0, published in June 2026, requires companies to account and report their inventory in accordance with the GHG Protocol standards and guidance, in the most recent effective versions. A target set on a footprint with no recorded base year and no recalculation policy will not hold.
- You have a footprint that nobody could verify. Scope 2 is reported one way only, scope 3 is a spend estimate with no screening behind it, the boundary predates two acquisitions and the factors cannot be traced. It needs rebuilding before a verifier, an auditor or the revised standard gets to it.
Aim for a figure you can repeat and defend every year. Reductions come from acting on what the inventory shows, not from the inventory itself.
Business benefits
How a GHG Protocol inventory pays its way
An inventory earns its cost when it settles questions the business would otherwise argue about: which figure the annual report uses, which sites and suppliers drive the total, and whether a fall in emissions came from action or from a new electricity factor.
- One figure, many requestersThe same scope 1, 2 and 3 totals answer the customer questionnaire, CDP, the IFRS S2 or ESRS disclosure and the target submission, so no two documents disagree.
- Scope 3 you can steerScreening all 15 categories shows where value chain emissions sit, so supplier engagement starts with the largest categories, not the easiest.
- Energy contracts that countLocation-based and market-based scope 2 side by side, with renewable contracts counted only when the instruments meet the Scope 2 Quality Criteria.
- Reductions that survive scrutinyA base year, a written recalculation policy and consistent methods, so a lower total after an acquisition or a divestment still compares like with like.
- A quicker, cheaper verificationBoundaries explained, factors referenced and data reconciled before the verifier arrives, so verifier days go on testing evidence, not locating it.
- Ready for the next standardMethods documented choice by choice, so the joint GHG Protocol and ISO standard becomes a structured update rather than a fresh start.
Judge it on a few measures: the share of emissions from primary data, verifier findings year on year and emissions per unit of output. A thicker workbook is not a climate outcome.
Requirements
What are the main GHG Protocol requirements?
The Corporate Standard is an accounting standard, not a management system standard, so it has no harmonised clause structure. It runs to eleven chapters, some setting requirements and others giving guidance only; the Scope 2 Guidance amends it and the Scope 3 Standard extends it along the value chain. The table maps each part to what your team produces; your inventory is checked against the documents themselves during the programme.
| Chapter | What it requires of you | What it looks like in practice |
|---|---|---|
| 1 GHG accounting and reporting principles | Apply relevance, completeness, consistency, transparency and accuracy to every accounting decision | A methods note recording each boundary choice, estimate and exclusion with the reason for it |
| 2 Business goals and inventory design | Design the inventory around its uses: disclosure, targets, customer requests, risk and reduction planning | A statement of intended users and uses that sets the level of detail |
| 3 Setting organisational boundaries | Consolidate emissions by the equity share approach or a control approach, financial or operational | A legal-entity and site list showing ownership, control and the approach applied to each |
| 4 Setting operational boundaries | Account for and report scopes 1 and 2 separately as a minimum; scope 3 is optional under this standard | A source register by scope: fuels, process and fugitive emissions, vehicles, purchased energy and the scope 3 categories covered |
| 5 Tracking emissions over time | Set a base year and recalculate it when structural changes, methodology changes or errors would distort comparison | A base-year record, a recalculation policy and a log of every recalculation made |
| 6 Identifying and calculating GHG emissions | Identify sources, choose calculation approaches, collect activity data and emission factors, and bring the results together at company level | Activity data traced to invoices and meters, a factor library with source and year, calculations by gas in carbon dioxide equivalent |
| 7 Managing inventory quality | Guidance on a quality system for the inventory: data checks, documentation and uncertainty | Data owners, review steps and an uncertainty assessment for the largest sources |
| 8 Accounting for GHG reductions | Guidance on showing reductions as the change in the inventory over time, with project-based reductions and offsets kept apart | Initiatives tracked against the base year; any offsets or credits recorded outside the inventory totals |
| 9 Reporting GHG emissions | Report scope 1 and scope 2 separately, with the boundary, base year, methods, data sources and exclusions disclosed | An inventory report an outside reader can follow, each figure traceable to its calculation |
| 10 Verification of GHG emissions | Guidance only: the standard is designed to produce a verifiable inventory but does not set out how verification is conducted | An audit trail an independent verifier can test; the verification standard, often ISO 14064-3, agreed with the verifier |
| 11 Setting GHG targets | Guidance on designing a reduction target: its type, boundary, base year and completion date | A target stated against the recorded base year and tracked from the figures the report uses |
| Scope 2 Guidance (2015) | Where your markets offer contractual instruments, report scope 2 twice, by the location-based and the market-based method, with instruments meeting the eight Scope 2 Quality Criteria | Grid-average factors for one figure; supplier rates, certificates and contracts, with their evidence, for the other |
| Scope 3 Standard (2011) | Account for all scope 3 emissions across 15 categories, eight upstream and seven downstream, disclose and justify any exclusion, and report scopes 1 and 2 alongside | A screening of every category, supplier or spend data for the significant ones, and a reason for each exclusion |
What does useful GHG Protocol evidence look like?
A boundary document naming each entity and the consolidation approach, a source register by scope, invoices and meter readings reconciled to activity data, fuel, fleet and refrigerant records, the instruments behind the market-based scope 2 figure, supplier and spend data for the scope 3 categories quantified, a factor library citing source and year, a version-controlled calculation, the base-year record and recalculation log, and the reviewed inventory report. All of it lives in Effivity from the first workshop, so a verifier sees a maintained inventory, not a year-end reconstruction.
GHG Protocol requirements explained, scope by scopeInventory and verification
How do you build and verify a GHG Protocol inventory?
The inventory comes first; verification, where someone requires it, comes second. The GHG Protocol publishes the rules and neither certifies organisations nor verifies inventories. Sterling works with you on the boundaries, calculations, evidence and report, and an independent verification body tests the result and issues its own statement.
- 01Set the purpose, the boundary and the reporting year.Agree who will use the figures, the entities and sites, the consolidation approach, the reporting period and whether verification is needed, and at what level of assurance.
- 02Gap analysis: compare today's data and methods with the standards.The gap analysis tests existing calculations, factor sources, scope 2 treatment and scope 3 coverage against the Corporate Standard, the Scope 2 Guidance and the Scope 3 Standard, keeps what holds and assigns actions, owners and dates.
- 03Build the inventory and its evidence trail.Sources registered by scope, data owners assigned, factors referenced, both scope 2 figures calculated, scope 3 screened and the significant categories quantified, and the base year recorded.
- 04Write the report, review it internally, correct what is found.An internal audit of the inventory against the standards and a management review of the report; we raise what a verifier would raise, first, and close it with evidence.
- 05Complete the independent verification, where it is required.The verification body agrees scope, criteria, level of assurance and materiality, reviews the documentation, visits sites as its risk assessment requires and issues its statement; discrepancies are corrected before it is final.
- 06Embed and review.Data collection runs through the year, factors and boundaries are updated, the recalculation policy is applied and the next inventory starts from a live system, not from last year's workbook.
Judge the route before the price. No GHG Protocol certificate exists, so an offer of one is a warning. Where verification is needed, ask which body will verify, who accredits it, and which verification standard, level of assurance and materiality it will apply, then confirm the answers with the bodies themselves. How to choose a credible GHG Protocol provider · The certification buyer's checklist
Cost
How much does a GHG Protocol inventory cost?
A reliable price depends on what the inventory has to cover. A single-office service business reporting scopes 1 and 2 is a different piece of work from a manufacturer screening all fifteen scope 3 categories across plants in several countries. Sterling's commitment is a proposal in which every element is visible and nothing is added later before work begins.
| Cost component | What affects it |
|---|---|
| Consulting and implementation | Entities, sites and sources, the scope 3 categories quantified, the condition of your data and how much of the work your team carries (Design™ or Drive™) |
| Independent verification | Only where required: verifier days depend on the boundary, the scopes and categories covered, the sites visited and the level of assurance, plus travel and the annual repeat |
| Data, metering and emission factors | Sub-metering where invoices cannot be split by site, supplier data requests for scope 3, and any factor database licences your countries need |
| Internal resources | Time from finance, procurement, facilities, fleet and the site contacts who own the data, and from whoever signs off the report |
| Software and learning | Included in a Sterling engagement: Effivity as the inventory workspace and Sterling Academy access for your people, with users, courses and access period confirmed in the proposal |
| Continued support | Next year's inventory, internal reviews, factor and base-year updates, refresher learning and the move to the revised standard under Sustain™ and Revise™ |
What moves the price
- Entities, sites and countries in the boundary, and the consolidation approach
- How many scope 3 categories are relevant, and how much supplier data they need
- Whether a base year, factor sources and a previous inventory exist, and how far they stand up
- Whether verification is required, and at limited or reasonable assurance
- The deadline, the reporting languages and any customer, investor or group requirements
What a Sterling proposal always shows
- Deliverables, responsibilities, assumptions and exclusions, set down in writing
- Verification-body fees, where verification applies, shown separately for a like-for-like comparison
- Effivity, training and Academy access itemised at no additional cost
- Payment milestones linked to deliverables, not to calendar dates
- One all-inclusive proposal. No surprises, ever
Timeline
How long does a GHG Protocol inventory take?
For most organisations, three to six months from kick-off to a complete first inventory, and the pace is set by data rather than by consultants. The reporting year has to be closed, invoices matched to sites, refrigerant and fleet records found, contractual instruments collected for the market-based figure and supplier data requested for scope 3. We plan backwards from your deadline, with milestones your team tracks in Effivity.
| Phase | What determines the pace |
|---|---|
| Purpose, boundary and gap analysis | Access to the group structure, the site list, invoices, previous calculations and the people who hold the data |
| Scope 1 and 2 build | The number of sites and sources, metering gaps, and how quickly energy contracts and certificates can be evidenced |
| Scope 3 screening and quantification | How many categories are significant, and how quickly suppliers, logistics providers and finance supply data |
| Report, review and verification | The internal audit and management review of the report, then the verification body's availability, level of assurance and site visits |
If a questionnaire deadline, a disclosure date or a target submission sets the timetable, tell us at the first call. We will say plainly what is achievable and which data to request in the first fortnight. An inventory date offered before anyone has looked at your utility bills is a guess dressed up as a plan.
Challenges
Common GHG Protocol inventory challenges
GHG Protocol inventories go wrong in the same five places, and each has a practical fix.
Scope 2 is reported one way only.
Grid averages and renewable certificates are mixed in one figure, or only the market-based result is shown. Where contractual instruments exist in your markets, the Scope 2 Guidance requires both. We calculate each method separately and test every instrument against the Scope 2 Quality Criteria.
Scope 3 is a spend estimate nobody believes.
One spend-based calculation hides the real drivers, or the largest categories are missing. We screen all fifteen, quantify the significant ones, justify each exclusion as the Scope 3 Standard requires and replace averages with supplier data year by year.
The consolidation approach was never chosen.
Joint ventures, leased buildings and franchised sites are counted by one team and left out by another. We agree the approach with finance and legal, apply it to every entity and record why each one is in or out.
Last year's reduction was a divestment, not an achievement.
A sale, a method change or a corrected error moved the total, and the base year was never touched. We write the recalculation policy, apply it when a trigger occurs and log it, so trends compare like with like.
The inventory will change when the standards do.
The corporate, Scope 2 and Scope 3 rules are all under revision. We document every method choice, so the joint standard becomes a review of recorded decisions rather than a new inventory.
Your engagement
What your GHG Protocol engagement includes
Your agreed scope covers what a verifiable inventory and a capable team need. Many providers hand over a spreadsheet and leave the rest to you; a Sterling engagement covers the whole journey, with one team and one all-inclusive proposal.
Purpose, boundaries, gap analysis and inventory plan
Intended users, consolidation approach and reporting year agreed, the gap analysis done and a plan with owners and dates in place before work starts.
Inventory, methods note and report
Source register, factor library, scope 2 by both methods, scope 3 screening and calculations, the base-year record and the inventory report, built with your data owners on Sterling's templates.
Effivity ISO & GRC software
The inventory workspace is set up in Effivity at the first workshop, included with the engagement at no additional cost.
Training for everyone
Internal auditor training for the people who will review the inventory, as applicable to your standard, and preferential Sterling Academy course access and special pricing, including complimentary awareness training for your people as part of the engagement.
Internal audit and management review
Conducted or facilitated as agreed, with each finding corrected and evidenced before any verifier is engaged.
Verification readiness and support
Where verification is in scope: preparation for the verifier's documentation review and site visits, and support with discrepancies until the statement is issued.
There is no GHG Protocol certificate; where verification is in scope, the opinion belongs to the independent verification body, and Sterling neither verifies nor issues the statement.
How we deliver
How Sterling supports your GHG Protocol implementation
Every GHG Protocol engagement runs on Sterling OS™, our delivery operating system: five phases, each with defined deliverables, decision owners and evidence. You decide how much of the work your team takes on; the method, the software and the accountability stay constant.
- 01Design™Guided implementation: your sustainability lead and data owners build the inventory using Sterling's structure, templates, workshops and coaching.
- 02Drive™Fully managed consulting: Sterling consultants carry the agreed work, from the boundary document and scope 3 screening to the inventory report, alongside your data owners.
- 03Sustain™After the first inventory: annual data cycles, internal reviews, factor and base-year updates, verification readiness and training for new data owners, year after year.
- 04Automate™The inventory running in Effivity: boundaries, sources, factors, data requests, evidence, reviews, actions and management review in a single workspace.
- 05Revise™The joint GHG Protocol and ISO corporate standard when it is published, and changes in entities, sites, methods, factors or the disclosure rules that use your figures.
At kick-off we agree the engagement team, the weekly working session, the deliverables and who decides what, so a missing refrigerant log is found in the first month rather than by the verifier.
How Sterling OS™ worksOften combined with
Standards organisations pair with GHG Protocol
- AA1000AA1000 implementation and requirements: apply the AccountAbility Principles and SES, then prepare for AA1000AS v3 assurance by a licensed provider.
- B Corp CertificationB Corp certification made clear: the new B Lab Standards, Foundation Requirements, seven Impact Topics, the audit route and how Sterling prepares you.
- CBAMCBAM compliance and requirements explained: authorised declarant status, the 50-tonne threshold, verified embedded emissions and how Sterling helps you prepare.
- CDPCDP disclosure consulting: a complete, evidenced response on climate, forests and water, prepared with your team.
- CSDDDCSDDD compliance and requirements after Omnibus I: scoping, risk-based due diligence, complaints, monitoring and the 2029 start, delivered in one all-inclusive proposal.
- CSRD / ESRSCSRD and ESRS Sustainability reporting consulting: double materiality, ESRS disclosures and data prepared for limited assurance of your statement.
Effivity · GHG Protocol inventory software, included in every engagement
How Effivity helps you fulfil, automate and simplify the requirements of the GHG Protocol Corporate Standard (2004).
Every Sterling GHG Protocol engagement includes Effivity, the ISO and GRC automation platform built by the Sterling group and used in 50+ countries. Your consultant configures an inventory workspace within the agreed scope, holding the entity and site list, source register, factor library, data requests with their evidence, scope 2 instruments, scope 3 screening, base-year record, reviews and actions in one place, so the verifier reviews live records rather than exports. For Sterling consulting clients, Effivity comes included with the engagement, at no additional cost.
Entities, ownership and control
The entity and site list with ownership shares, control status and the consolidation approach, changes logged as the group acquires, sells or restructures.
Sources by scope
A register of every source under scope 1, 2 or 3, with the scope 3 screening, the categories quantified and the justification for each exclusion.
Activity data and factors
Data streams with owners, frequencies and attached invoices or meter readings; a factor library with source and year; calculations traceable from each input to the scope totals.
Base year and recalculation
The base-year inventory, the recalculation policy and a log of every structural, methodological or error-driven recalculation, so year-on-year comparisons stay accurate.
Checks, owners and uncertainty
Collection and review procedures with versions and approvals, checks assigned to defined roles, and the uncertainty of the largest sources on record.
The inventory report
The report assembled from the registers: both scope 2 figures, scope 3 by category, the base year, methods and exclusions, with earlier years kept for any restatement.
Verification plan and findings
The verifier's scope, criteria, level of assurance and materiality on record, evidence shared from the workspace, discrepancies logged and closed, and each statement filed against its reporting year.
Your own forms, workflows and dashboards
Supplier data requests, site checklists and dashboards shaped to how you work, without code, and extended to environmental or energy management when you integrate.
What this means at the verification
A verifier typically asks for the boundary document, the invoices behind the largest sites, the scope 2 instruments, the scope 3 screening, the base-year record and the internal review. In Effivity each is a screen with dates, owners and evidence attached, not a folder assembled in the final week, and after the statement Sustain™ continues in the same workspace.
In your engagement
- Subscription included with the engagement, at no additional cost
- Configured by your Sterling consultant within the agreed scope
- Existing workbooks, factors and prior years migrated, not retyped
- Admin and user training for the sustainability team and data owners
- Modules for EMS, EnMS, QMS and ISMS when you integrate
GHG Protocol client experience
Client letters on file, available on request.
Signed client letters for the GHG Protocol are available on request. The client feedback wall lists every letter by standard.
Integrated programmes with the GHG Protocol in scope
How a GHG Protocol inventory runs inside an integrated programme.
- 01Integrated management systems
Supplier to global brands: an ISO 14001 system with a GHG Protocol inventory at its centre
How such a programme typically runs: the aspects register and the inventory's source register are built in the same workshops, so fuel, refrigerant and energy data each have one owner; scope 3 screening follows the purchasing categories finance already reports; one set of totals answers customer questionnaires and CDP; the certification body audits the environmental management system, while a separately accredited verification body verifies the inventory where customers require it.
Sterling Academy · GHG Protocol e-learning
Train the people whose work creates the data, not only the sustainability lead.
Most inventory errors start before the calculation: a fuel card never reconciled, a refrigerant top-up not logged. Sterling Academy delivers e-learning for everyone who feeds the inventory and for the people who run it: video lessons with practice checkpoints, a final exam and a numbered Certificate of Completion for each learner, verifiable online. Through their Sterling consultant, consulting clients receive preferential Sterling Academy course access and special pricing, including complimentary awareness training for their people as part of the engagement.
- GHG Protocol awareness for every employee who handles energy, fleet, purchasing or travel data
- Practitioner courses for the sustainability lead, the energy manager and the owners of the source register
- Internal auditor training for the people who will review the inventory, as applicable to your standard, as part of the engagement
- Learner progress by site and function, and a training record the verifier can see
- New data owners trained as they join, so competence keeps pace with each reporting year
- A Sterling consultant available when a learner has a question
Keep exploring
Explore more about GHG Protocol
Watch a video on how to build a GHG Protocol emissions inventory here.
Watch a video on GHG Protocol requirements here.
Why Sterling
Want a successful GHG Protocol inventory? Come to Sterling.
Whether you account for one company or consolidate subsidiaries across several countries, Sterling helps you run one method with clear data ownership in every entity, working through differences in grid factors, contractual instruments, supplier maturity and local disclosure rules so the group total holds together.
Management systems in 60+ countries since 2003
Environmental, energy and carbon accounting work for manufacturers, contractors, logistics operators, banks, hospitals and service groups, with one engagement team accountable across every country in your boundary.
All-inclusive proposal
Consulting, Effivity, training and Academy access in one proposal, with any verification-body fees shown separately. No surprises, ever.
An inventory your data owners can run
Less documentation and maximum effectiveness: data requests, factors, evidence, training and software connected to how finance, procurement, facilities and the sites already work, so next year's inventory is an update, not a rebuild.
Expert and experienced consultants
Consultants who have advised on environmental and climate programmes across sectors and countries since 2003, and who build your inventory properly the first time, so verification confirms what is already sound.
The Sterling Promise
What our GHG Protocol inventory success guarantee means
We stay with you until the GHG Protocol outcome agreed in your engagement is achieved: a complete inventory and report and, where verification is in scope, the statement, supporting you through implementation, preparation and any findings. Clear explanations, practical delivery, included software and training for your people leave a capability you keep, not a number nobody can reproduce.
The engagement defines the standards applied, the boundary, the scopes and categories, any level of assurance, the outcome and the responsibilities. Your organisation provides accurate information about its entities, sites and activities and operates the agreed procedures. Where verification applies, the independent verification body forms and keeps its own opinion. Our commitment covers the agreed inventory and verification support; it does not promise a particular emissions figure or reduction.
After the first inventory
What happens after your first GHG Protocol inventory?
The first inventory is the hardest; the real test is whether the second is easier. Data is checked on schedule, factors are updated, the recalculation policy is applied when the company changes and spend-based scope 3 estimates give way to supplier data. A verification statement covers one reporting period, so those who rely on your figures expect the cycle to repeat every year.
Under Sterling OS™ Sustain™ we review data quality, open findings, boundary changes and the revision timetable with you alongside the planned internal and management reviews, so the inventory keeps running between reporting seasons.
FAQs
Frequently asked questions about the GHG Protocol
Is there a GHG Protocol certification?
No. The GHG Protocol publishes accounting standards; it does not certify organisations or verify inventories, and the Corporate Standard states that it does not set out how verification should be conducted. What you can have is an inventory prepared in conformance with the standards and, where someone relies on it, a statement from an independent verification body at limited or reasonable assurance. A "GHG Protocol certificate" is a product of whoever sells it, not of the GHG Protocol.
Is a GHG Protocol inventory mandatory?
Not in itself: the GHG Protocol is voluntary. It becomes a requirement through the rules and programmes that adopt it: IFRS S2, the SBTi's net-zero standard, and customers and CDP asking for figures in its terms.
What are the 15 scope 3 categories?
Upstream: purchased goods and services; capital goods; fuel- and energy-related activities not included in scope 1 or scope 2; upstream transportation and distribution; waste generated in operations; business travel; employee commuting; upstream leased assets. Downstream: downstream transportation and distribution; processing of sold products; use of sold products; end-of-life treatment of sold products; downstream leased assets; franchises; investments.
Do we have to report scope 3?
Under the Corporate Standard, scopes 1 and 2 are the minimum and scope 3 is optional. If you report under the Scope 3 Standard, all scope 3 emissions must be accounted for, with any exclusion disclosed and justified. Disclosure rules and schemes add their own expectations: IFRS S2 asks for scope 3 emissions, and the SBTi sets coverage rules for targets.
What is the difference between location-based and market-based scope 2?
The location-based method applies average emission factors for the grids where you consume energy. The market-based method reflects the contractual instruments you hold, such as supplier-specific rates and certificates, provided they meet the Scope 2 Quality Criteria. Companies with operations in markets that offer such instruments report both figures, each labelled by method.
Should we use the GHG Protocol or ISO 14064-1?
Often both. The GHG Protocol supplies the scope vocabulary that questionnaires, disclosure standards and target schemes use; ISO 14064-1 specifies requirements for an organisation's inventory and pairs with ISO 14064-3 for verification. An inventory built to one can be mapped to the other, and in July 2026 the two organisations announced one joint corporate standard, with publication planned for Q4 2028.
Who verifies a GHG Protocol inventory, and does Sterling?
An independent verification body, typically accredited for greenhouse gas verification to ISO/IEC 17029 with ISO 14065 and working to ISO 14064-3, with the GHG Protocol standards as its criteria. For sustainability reports, assurance practitioners may also work to ISSA 5000, effective for periods beginning on or after 15 December 2026. Sterling prepares the inventory and supports you through verification; it does not verify and does not issue statements.
Which consolidation approach should we choose?
The Corporate Standard allows the equity share approach or a control approach. Equity share follows your economic interest in each operation; financial control follows the ability to direct its financial and operating policies; operational control follows the full authority to introduce and implement its operating policies. Choose by group structure and disclosure needs, then apply the approach across the group and record why.
The GHG Protocol is being revised. Should we wait?
No. Consultation on the joint standard is planned for Q2 2027 and publication for Q4 2028, while the people asking for your figures want them now, on the current editions. The boundary, data, factors and base year you build today carry forward; only the methods that change will need a Revise™ review.
Before the first call
Prepare a useful GHG Protocol readiness brief
No calculation or boundary document is needed before the first conversation. A short account of the business and of who wants the figures is enough. Seven questions:
- Who is asking for the inventory, a customer, an investor, a regulator, CDP, a target scheme or the board, and for which reporting year?
- Which legal entities and sites should it cover, and how does the group own or control them?
- Which activities burn fuel, use refrigerants, run vehicles or purchase electricity, heat, steam or cooling?
- Do you hold renewable electricity contracts or certificates, and in which countries?
- Which scope 3 categories are likely to matter most: purchased goods, freight, travel, the use of your products, investments?
- What data, calculations or earlier disclosures exist today, and who holds them in finance, procurement and the sites?
- Is verification required, at what level of assurance, and is there a deadline to plan around?
With these answers we can scope the work and write a realistic proposal. They prepare a conversation; they are not a scored assessment or a verification opinion.
Don’t be fooled by "GHG Protocol certified" claims
If it takes ten days, it is not a verified GHG Protocol inventory.
An inventory is worth having when its boundary, scopes and methods answer the question a customer, investor or regulator asked, and when it would survive someone else recalculating it. The market also sells "GHG Protocol certificates" the GHG Protocol never issued, calculators that turn a spend total into a badge, and consultants who calculate, verify and certify under one invoice. They cost less, until someone checks.
How to choose a credible GHG Protocol provider
- Ask what exactly you will receive. The GHG Protocol issues no certificates, so a provider offering one is selling its own paper; the real outputs are an inventory, a report and, where required, a statement from an independent verifier.
- Ask who will verify, if verification is needed, and check that body's accreditation for greenhouse gas verification with the accreditation body itself.
- Ask how scope 2 and scope 3 will be handled. A single scope 2 figure where contracts exist, or scope 3 without a screening of all 15 categories, is a shortcut the next reader will find.
- Identify who carries each task, which costs are separate, and what happens when the verifier raises a discrepancy.
- Ask what your data owners will learn and where the inventory will live. Without training and a system, the calculation leaves with the consultant.
- Walk away from "certified in 7 to 10 days", "we calculate and verify" and one invoice for the inventory and its statement. Whoever built your figures cannot be the one who verifies them.
Talk to a consultant
Plan your GHG Protocol inventory with confidence.
Tell us your goals, locations and target date. We’ll help you define the scope, timeline and next steps.
hello@sterling-grc.com+1 201 263 4443 (global headquarters) · your nearest office and its number are at the top of this page
What would you like to achieve?
Choose a starting point. The enquiry form takes about a minute.
Book my free discovery callContinue to the enquiry form to share your details. Please do not include passwords, sensitive personal information or confidential files. A Sterling consultant replies within one working day. Privacy notice