The trust-building layer of PACT Methodology v3.0, on top of the PCF calculation rules: two data-quality metrics that must accompany every PCF exchange, plus a staged roadmap for independent verification of the calculation itself.
The sections below describe the v3 (2025) state; the v2 → v3 delta section documents what changed from Pathfinder Framework v2 (2023).
Primary Data Share (PDS)
Definition: the percentage of a PCF’s emissions calculated using primary (company-specific) activity data and emission factors, as opposed to secondary/estimated data.
Status: mandatory now, not deferred. The source states this three times with identical unqualified “shall” language and no future-date attached:
- “Companies shall assess the primary data share (PDS) of the PCF excluding biogenic CO2 uptake” (Sec. 4.1)
- “Companies shall calculate and report PDS as part of the PCF data exchange” (Sec. 4.2.2)
- “the PDS shall be calculated and exchanged” (Sec. 4.2.2)
This is in explicit contrast to DQR, which the same sentences defer to 2027 onwards (see below) — the document consistently treats PDS and DQR as different in their timing, not as a pair sharing one deadline.
⟨Nuance flagged during ingest, per Martin Pompéry’s request to re-verify: the reporting obligation for PDS is immediate, but the meaningfulness of a company’s PDS score is ecosystem-dependent — upstream PDS can only be
0% if suppliers also report their own PCF and PDS (“companies shall request PCFs and their corresponding PDS from their suppliers”), and the document frames actual primary-data adoption as something to “increase… over time.” So the KPI itself is a present, ongoing disclosure requirement, while the network-wide value it reports on is explicitly expected to improve prospectively as more companies participate.⟩
Formula — weighted average across PCF components by absolute contribution:
PDS_product (%) = Σ ( |PCF_i| × PDS_i ) / Σ |PCF_i|
where i ranges over each component (input/output) in scope, and |PCF|
is the absolute value of the PCF excluding biogenic CO2 uptake (i.e. before
netting removals against emissions).
Rules: an input only counts as primary data if both its activity data and its emission factor meet PACT’s primary-data definitions (Table 9). If a component’s PDS is unknown, companies must apply a 0% PDS score to it (worst case, not an omission).
Data Quality Ratings (DQR)
Definition: three separate indicators scoring how representative the underlying data is:
- Technological representativeness
- Geographical representativeness
- Temporal/time representativeness
Each is scored 1 (best) to 5 (worst) per a defined data quality assessment matrix (Table 12), calculated via the same weighted-average-by-absolute- contribution logic as PDS.
Status: mandatory from 2027 onwards (“only required by end of 2027, i.e. 31.12.2027” — the qualifier appears on footnotes 73 and 74, attached specifically to the DQR sentences). If upstream DQR is unknown, companies must apply the worst-case score (5) to that component — same “declare the worst case rather than omit” pattern as PDS’s 0% rule.
Verification roadmap
Two time horizons, distinguished by what gets verified:
- Short-term (2023-2030): verify the PCF Calculation Model itself (the tool, spreadsheet, or platform a company uses) against a defined standard, at a “limited assurance” level, via an independent third party — not a review of every individual product calculation. Minimum review elements (Table 14/15): boundary alignment (cradle-to-gate), calculation standard used, characterization factors (100-yr GWP, IPCC AR version), unit of analysis, exempted-emissions disclosure (<3% cap), data quality/PDS/DQR calculation, data source transparency, and automated test-vector validation of the model’s outputs.
- Long-term (2030+): full PCF Program Certification — governance- level certification, not just the calculation tool (Table 16).
Verification dimensions spanning both horizons: Coverage, Conformance, Boundary, Level of verification, Provider, Process cycle (plus SME timing and reporting sub-dimensions).
SME accommodation: SMEs (EU definition: <250 employees, ≤€50M turnover or ≤€43M balance sheet) get a 2-year grace period on every requirement, counted from when that requirement first applies to larger corporates — e.g. short-term verification requirements become applicable to SMEs from 2027 onwards (2 years after they apply to non-SMEs).
What changed from Pathfinder Framework v2 (January 2023)
Everything above describes the v3 (2025) state. The v2 source is now in the wiki, so the deltas are documented rather than inferred. This is the clearest promised-vs-built evidence the wiki holds on PACT, because it compares a dated commitment against its own successor version.
The assurance roadmap shrank
v2’s Figure 17 set out three horizons; v3 has two. The dimension that disappeared is the destination:
| Dimension | v2 short-term 2023–2025 | v2 medium-term 2025–2030 | v2 long-term 2030+ |
|---|---|---|---|
| Level (degree of confidence) | Limited assurance | Limited assurance | Reasonable assurance |
In v3, a full-document search for “reasonable assurance” returns no hits. The only statement of assurance level is: “Companies are required to request third party verifiers to conduct a verification following a limited level of assurance.” v3’s long-term horizon changes what is certified (PCF Program Certification instead of PCF Calculation Model) but not the level of confidence.
The other v2 roadmap dimensions largely carry over: Coverage (corporate level → representative product/PCF system), Conformance (any recognized standard → PCR or sector guidance, else the Framework), Boundary (gate-to-gate with Scope 1+2 → cradle-to-gate), independent third-party provider throughout, process cycle annual → 3 years or earlier if variance >10%, evidence-pack guidance in Appendix D, and the SME 2-year lag. The full v2 table is transcribed on the v2 paper page.
⟨Inference: dropping reasonable assurance is a material retreat. Reasonable assurance is the audit level applied to financial statements; limited assurance is a negative-form opinion. A 2023 commitment to reach the former by 2030 was removed, without comment, in the 2025 revision.⟩
Two deadlines slipped
| Item | v2 (Jan 2023) | v3 (2025) |
|---|---|---|
| PDS mandatory from | 2025 | now (unqualified “shall”) |
| DQR mandatory from | 2025 | 31.12.2027 |
v3 states its own reason for the DQR slip: “As the data quality assessment matrix has been updated from PACT Methodology Version 2, companies shall calculate and report DQRs from 2027 onwards” (§4.2.1). The deadline moved because the instrument was rebuilt — a self-documented cause, not a silent delay.
The DQR instrument was narrowed
| v2 | v3 | |
|---|---|---|
| Indicators | 5: technological, geographical, temporal, completeness, reliability | 3: technological, geographical, temporal |
| Scale | 1–3 (Good / Fair / Poor, Table 9) | 1–5 |
Completeness and reliability — the two indicators that scored the data collection process rather than the data’s representativeness — were dropped. The finer 1–5 scale increases resolution on what remains.
One rule got stricter
Exempted emissions: v2 required <1% per individual process AND <5% in aggregate; v3 requires <3% in aggregate only. Single-threshold, and the aggregate cap tightened from 5% to 3%. See PACT PCF Calculation Methodology.
⟨Inference: the direction of travel is mixed, not uniformly a weakening. The calculation rules tightened while the assurance ambition and the quality instrument were scaled back. A fair reading is that PACT traded reachable rigour in the calculation for deferred rigour in the audit.⟩
Contradiction carried, not resolved
v3 is internally inconsistent about its own short-term horizon: its prose says “In the short-term (2025-2030)…” while its roadmap table says “Short term 2023–2030”. v2’s three-horizon scheme had 2023–2025 / 2025–2030 / 2030+. ⟨Inference: the v3 prose sentence appears to be an imperfectly updated carry-over of v2’s medium-term horizon.⟩ Both v3 readings are recorded here; neither is treated as authoritative.
What the wire format carries ⟨2026-11-06⟩
⟨Added from the Technical Specifications for PCF Data Exchange v2.2.0 (April 2024) — the exchange layer belonging to Framework v2. Until now this page described the metrics as the methodology defines them; this is how they travel.⟩
On a CarbonFootprint, both metrics are carried: primaryDataShare
(a percentage) and dqi, an object of type DataQualityIndicators.
DataQualityIndicators has five members — technologicalDQR,
temporalDQR, geographicalDQR, completenessDQR, reliabilityDQR — each
of which “MUST be a decimal between 1 and 3 including”, plus
coveragePercent, the share of the PCF assessed under the >5 % emissions
threshold. The shape matches Framework v2 exactly, including Table 9.
The deadlines in the data model and in Methodology v3 do not agree.
The wire format says: for reporting periods ending before 2025, at least one
of primaryDataShare or dqi MUST be defined; “for reporting periods
including the beginning of year 2025 or after, this property MUST be
defined” — written against both. The same rule repeats on each DQI
member (“Each property is optional until the reporting period includes the
beginning of calendar year 2025, or later, when all properties MUST be
defined”). Methodology v3 defers DQR to 31.12.2027.
⟨Inference: a v2.2-conformant host must reject or flag a 2025 footprint without a DQR; a v3-conformant calculator need not produce one until 2028. The two documents are from different generations and the v3 Tech Specs presumably move the date — but this wiki holds no source for that, and the gap is live for anyone implementing against the published pair. Note also the direction of the deferral: the data model’s 2025 deadline is earlier than the methodology’s 2027 one, so the relaxation happened on the methodology side.⟩
Assurance travels as an unverifiable claim. The optional assurance
object carries coverage, level, boundary, providerName,
completedAt, standardName, comments — assertions about an audit, with
nothing attached that a recipient could check. Two details:
leveltakeslimitedorreasonable, and the §7.10 examples ship"level": "reasonable". The wiki records that the phrase “reasonable assurance” does not appear in Methodology v3 at all. The field outlived the ambition.providerNameis mandatory only by mistake: it “was incorrectly and unintentionally published in V2 of the Technical Specifications as Mandatory, [and] will be reverted to Optional in version 3”.
And the exemption cap moves the other way in the schema.
exemptedEmissionsPercent is bounded at 5 % here, with the note that “the
upper boundary of this property (currently 5) will be removed in
version 3 of the Technical Specifications” — while
the methodology tightened the rule to <3 %
aggregate. ⟨Inference: reconcilable if the schema is deliberately getting
out of the methodology’s way, leaving the threshold to be enforced where
it is defined rather than hard-coded in a data type. Neither document says
so; recorded as a divergence, not resolved.⟩
External view: PDS as one half of a two-part mechanism
The Carbon Accounting Landscape Review (ICC, 2026) names PDS and CBAM’s tightening default values as the “two complementary mechanisms — disclosure and consequence” driving the shift to primary data (§6.1). Its Criterion H (Operability) also holds that a decision-grade system does not require perfect primary data on day one — only a rule-governed pathway that distinguishes data tiers, flags quality, and creates incentives to improve; see decision-grade carbon-data criteria.
Cross-references
- PACT PCF Calculation Methodology — the calculation rules these metrics assess the quality of
- PACT Methodology v3.0 (WBCSD, 2025) — source paper
- Pathfinder Framework v2 (WBCSD, 2023) — predecessor; Figure 17 assurance roadmap
- Tech Specs for PCF Data Exchange v2.2 (2024) — how PDS, DQI and assurance travel on the wire
- Pathfinder Network — network context these metrics are exchanged over
- WBCSD
- Decision-grade carbon-data criteria — Criterion H on data-tier pathways
- The Carbon Accounting Landscape Review (ICC, 2026) — §6.1 on PDS and CBAM as disclosure/consequence
Sources
- PACT Methodology v3.0 (WBCSD, 2025) —
sources/whitepapers/2026-08-10-pact-methodology-v3.0/pathfinder-methodology-v3.0.md, Sections 4.1, 4.2, 5.3 - Pathfinder Framework v2 (WBCSD, Jan 2023) —
sources/standards/2026-10-29-pact-methodology-v2-framework-2023/…md, §2.3, §4.3, §5, Figure 17 (recovered from page image), Table 9 - PACT, Apr 2024) —
sources/standards/2026-10-29-pact-data-exchange-protocol-v2.2.md, §5.2 (CarbonFootprint), §5.3 (DataQualityIndicators), §5.4 (Assurance)