Getting Scope 3 Data Ready (2025): GHG Protocol vs SBTi requirements explained

TL;DR

GHG Protocol is the accounting rulebook for building a complete, consistent Scope 3 inventory. SBTi evaluates your targets and coverage and expects credible methods and documentation.

Get "report-ready" by mapping categories, choosing methods — spend → activity → supplier specific — version locking factors, and writing a short methods memo.

Get "SBTi-ready" by demonstrating coverage of most Scope 3 emissions, showing an upgrade plan to better data, and implementing governance, including QA and a recalculation policy.

1) GHG Protocol vs SBTi: who asks for what?

This section compares the role of GHG Protocol and SBTi. GHG Protocol defines what companies need to account for, while SBTi checks whether targets, coverage, ambition and governance are credible.

2) The Scope 3 data-readiness ladder

Rule of thumb: Start with L1 for coverage, then move material categories to L2/L3, and attribute savings at L4.

3) Category-by-category data map: minimums vs strong practice

This map shows what is typically enough for GHG Protocol reporting and what represents stronger practice for SBTi review.

4) Data inventory

Use this table to document each data domain, source system, owner, coverage, method, factor library, known gaps and fix plan.

A = Activity based, S = Spend based, SS = Supplier specific.

5) Factor governance

Good practice: Version-lock the factor pack used in the baseline and document any mid-year substitutions.

6) Methods & assumptions memo

1. Organizational & operational boundaries
2. Category methods — S/A/SS — with double-count controls
3. Electricity details — LB & MB; certificate criteria
4. Factor libraries — names, regions, vintages, version IDs
5. Data gaps & proxies — what/why; replacement plan & dates
6. QA rules — outliers; intensity benchmarks vs peers/priors
7. Recalculation triggers & thresholds

7) QA rules you can adopt today

Completeness: Every relevant Scope 3 category decisioned — Included/Not relevant — with rationale.

Double counting: Cat.3 vs Scope 1/2; Cat.1 vs Cat.2; Cat.4/9 vs internal logistics.

Factor sanity: Single geography & vintage per category unless justified.

Outliers: Flag site/category ±>30% YoY for investigation.

Intensity checks: tCO₂e per revenue/unit/FTE vs prior year and peer range.

Traceability: Data lineage from source system → transform → factor → result.

Lock & label: Factor pack/version and memo version are stamped in outputs.

8) Common edge cases and answers

Price inflation breaks spend factors: Deflate to baseline currency year; prioritize activity data in hot-spots.

Mixed geographies: Use weighted regional factors or split the population; avoid global averages for regionalized categories.

Certificates — market based electricity: Define quality criteria — geography match, vintage, additionality — and disclose scope of application.

WFH allocation: Apply a simple kWh/day assumption with regional emission factors; document survey cadence.

Partial supplier data: Combine SS data for top suppliers with L1/L2 for the long tail; label methods clearly.

PPAs/RECs timing: Align procurement period with reporting period; avoid double counting across entities.

9) Recalculation policy: Scope 3 data changes

Triggers:

Structural changes — M&A, outsourcing/insourcing — affecting Scope 3 boundary.

Factor/method updates that would materially shift base year totals.

Material data corrections.

Discovery of misclassification, for example Cat.1 vs Cat.2.

Materiality thresholds:

Relative: ≥ 5 to 10% change to base year total.

Absolute: ≥ [X,000] tCO₂e.

Change log:

10) Supplier primary-data request template

Use this template if you are not using DitchCarbon.

Subject: Request for primary emissions data & climate target status

Hello [Name],

We're improving the quality of our Scope 3 inventory. Please share:

1. Your latest Scopes 1 to 3 inventory — base year, methods, and factor sources.
2. Any plant- or product-level emission factors relevant to our purchases.
3. Your science-based target status — committed/validated — and evidence link.

We will attribute reductions from verified initiatives, for example recycled content, renewable energy, and logistics mode shift. Thank you.

11) Ready-to-paste reporting blocks

Scope 3 coverage statement example: [list], [~≥ two-thirds]

Electricity disclosure — Scope 2 — for context: both

12) FAQs

Do I need supplier specific data for all suppliers?

No, focus on material suppliers first; maintain coverage in the long tail with spend/activity methods.

Can I submit targets with spend based data?

Yes, if you show credible coverage and an upgrade plan for material categories.

What about FLAG?

If land-sector emissions are material in your value chain, prepare separate FLAG accounting and targets.

How DitchCarbon helps

No need to send supplier surveys: Know the status of all your suppliers with no need for manual work.

Coverage → precision: Map AP/GL for rapid Scope 3 coverage, then guide upgrades to activity- and supplier specific data where it matters most.

Version-locked factor packs: Region-aware libraries with vintages and provenance; clean audit trails in exports.

Supplier workflows: Collect primary data, track SBT commitment/validation, and attribute verified initiative impacts to categories.

Governance built-in: QA rules, outlier flags, and a baseline/target change log aligned to materiality thresholds.

SBTi-ready outputs: Paste-ready boundary statements, methods memos, factor registers, and coverage summaries for internal review or external assurance.

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