The 8 best supplier emissions data providers in 2026, compared

Four different kinds of company get sold as a supplier emissions data provider, and they are not substitutes for one another. Buying the wrong one is the most expensive mistake in this category, because it usually takes a full reporting cycle to notice. This page ranks the eight providers that hold an emissions figure against a named company, on the one question that separates them: what you get for a supplier that has not disclosed, which is most of any real list. It then sorts the wider market into its four groups and records which providers publish independent verification of their methodology.

DitchCarbon provides verified emissions data for over 2 million organisations, built on primary emissions data wherever it exists, so procurement, sustainability and finance teams can measure and act on supply chain and portfolio emissions from one source.

Provider list updated 22 September 2026. Factor database versions and verification status as at August 2026.

What counts as a supplier emissions data provider?

Four categories, four different questions answered. The mistakes listed here are the ones we watch teams make.

Emission factor databases

Coefficients that turn an activity or a spend line into kgCO2e. They contain no company identities at all: a factor exists for hot-rolled steel in the EU, never for a named steel company. They answer the question what does this kind of thing emit on average.

The mistake is buying one expecting supplier data. Apply a spend factor to an invoice and the result moves only when your spend moves. It cannot tell a best-in-class supplier from the worst in the same sector, so it cannot support a switching decision or evidence a reduction.

Company emissions databases

Datasets holding a figure against a named legal entity, so a supplier record or a spend line can be matched to a company-specific (primary) number. They answer the question what does this supplier emit.

Two mistakes here. The first is assuming coverage means the same thing across vendors: a database with twenty thousand companies can still return nothing for most of an accounts payable file, because that file is mostly private, unlisted, non-disclosing businesses. The second is treating a modelled company figure and a disclosed company figure as the same asset. They carry different assurance status and, in a portfolio, different PCAF data quality scores.

Supplier engagement and collection platforms

Software that sends a request to a supplier and returns whatever comes back. They answer the question what will my suppliers tell me if I ask them.

The mistake is buying one expecting coverage. The output is a response rate, not a dataset. A related mistake is treating a sustainability or maturity assessment as an emissions figure: a rating on a 0 to 100 scale is not a tonnage and cannot enter an inventory.

Carbon accounting platforms that also collect supplier data

Systems of record whose product is the calculated inventory and its audit trail. Collection is a feature that feeds the ledger. They answer the question what is my total footprint and can I report it.

The mistake is buying a platform to solve a data problem. A platform gives you the calculation engine, the categories and the report. It does not conjure supplier-specific (primary) figures it does not hold, and most fall back to spend factors for Category 1. Teams discover after implementation that they have bought a better container for the same secondary data.

The 8 best supplier emissions data providers in 2026

Ranked by fit for supplier-level and portfolio-level Scope 3 work. Three questions decide the order: where the figure comes from, what happens to a supplier that has published nothing, and whether the method behind each line is visible to your auditor. Sector specialists are ranked on their sector.

1. DitchCarbon

Verified emissions data for over 2 million organisations, built on primary emissions data wherever it exists: corporate GHG inventories, service and product-level carbon footprints, and supplier-specific emissions at spend, activity and product level, with a generic emission factor layer underneath for the organisations that have disclosed nothing. Records are matched to your list by entity resolution against DUNS, LEI and ISIN identifiers, every figure carries its source and change history, and each organisation records which of the four GHG Protocol methods produced its figure, so the share of a baseline still resting on a sector average is a filter rather than a claim. For a supplier that has not disclosed, a request goes out prepopulated with what can be found about it, and the sector average holds the line until something better arrives, shown as such. The Portal calculator is verified to ISO 14064-3, limited assurance, by UL Solutions, renewed annually.

What you still need afterwards: nothing for the baseline. Requests go out only where a primary figure would change the total, and the reporting platform you already run takes the output as its supplier and portfolio data layer.

2. Tracenable

Takes the figure a company disclosed and records it as disclosed, for around 5,000 companies, with the source document behind it. The record stops where the disclosure stops: a supplier that has not published gets no row, and nothing is allocated to what you bought. On a real accounts payable file, most of which is private and non-disclosing, that leaves most of the list empty and the allocation to your spend still to do. DitchCarbon starts from the same published disclosures, matches them to the legal entities on your list, allocates them to your spend, and closes the rest of the list rather than leaving it blank. Tracenable is not in our verification benchmark.

What you still need afterwards: a figure for every supplier that has not disclosed, the allocation of each disclosure to your spend, and a route to the suppliers whose number you want to improve. That is the baseline, not the finishing touch.

3. CDP

A figure exists for a supplier if that supplier completed the CDP questionnaire in that year. CDP Supply Chain lets you ask your own suppliers to complete it, so the coverage you end up with is your response rate, and the A to D score that comes back is a rating rather than a tonnage and cannot enter an inventory. For the suppliers who do respond, the disclosure is the same primary data DitchCarbon reads from the public record, so a CDP disclosure is one of the inputs to a DitchCarbon figure rather than an alternative to it, and a supplier who has already answered CDP can reuse that answer on their DitchCarbon profile instead of filling in another form. CDP is not in our verification benchmark.

What you still need afterwards: a tonnage for the suppliers who did not respond, which is most of them, and a way to turn the ones who did into a Category 1 line rather than a score. A CDP response is an input to that calculation, not the calculation.

4. S&P Global Sustainable1 (Trucost)

Where a company has not reported, S&P maps it to business activities, apportions its revenue across them and applies a modelled factor, and its documentation says gaps are filled so that no gaps remain. The result is a sector average with a company name on it, wherever the company has not disclosed. In a financed emissions calculation that figure scores PCAF data quality 4 however large the model behind it, and the record does not tell you which of your holdings are reported and which are modelled unless you ask. DitchCarbon shows that split per organisation as a filter, and moves a holding up the hierarchy when a disclosure or a prepopulated request produces one. We checked S&P for our verification benchmark and found no public software-level verification. Our S&P Trucost and MSCI comparison works through the reported and modelled shares in detail.

What you still need afterwards: to know which holdings are reported and which are modelled, and a way to move the modelled tail up the PCAF hierarchy, because a DQ 4 figure is what the model produces however many holdings it covers. Coverage of the book is the start of the financed emissions work, not the end of it.

5. MSCI

Reported where available, otherwise estimated from production or revenue, otherwise a sector average, in MSCI's own order. "Where available" is the part that decides the data quality of the result, and how much of your own book falls outside it is the question to put to them, because the estimated remainder cannot be inspected: the model is proprietary, which means you cannot see how a given holding's number was produced. DitchCarbon records the source document and the method for every figure, so an auditor can follow a holding from the number back to what the company published. MSCI is not in our verification benchmark.

What you still need afterwards: the proportion of your book that fell outside "where available", the document behind each reported figure, and an inspectable method for the estimated remainder, so a counterparty figure can be followed back when the assurance provider asks.

6. CarbonChain

Models emissions for metals and commodity suppliers at the level of the mine, smelter or plant, and produces figures for CBAM. The figure is a model of the asset rather than the supplier's disclosure, and the coverage is the commodity lines only, so the rest of a supplier list needs another source. Its methodology was verified by Bureau Veritas and validated by SGS in October 2022, which places it among the five verified platforms in our benchmark. DitchCarbon covers the whole list and holds the supplier's own disclosed figure where one exists; for a metals buyer, the two answer different lines.

What you still need afterwards: every non-commodity line on the list, and the supplier's own disclosed corporate figure where it exists, since an asset model is a model of the plant rather than what the supplier reported. The CBAM lines are covered; the Category 1 total is not.

7. Carbon Minds

Life cycle data for chemicals and plastics by production route and region. What you get is a factor for a product, not a figure for a company: two suppliers of the same polymer by the same route get the same number, so it cannot tell you which supplier to engage. It holds a TÜV testmark and a Together for Sustainability endorsement dated January 2024. On a DitchCarbon baseline, a product factor like this sits on the allocated product lines, with the supplier's own corporate figure carrying the rest of the spend with that supplier.

What you still need afterwards: a company-level figure for each supplier, because a route-specific product factor cannot tell two suppliers apart or say which one to engage. It belongs on the allocated product lines of a baseline that already exists.

8. Climatiq

An API over the main emission factor databases, ecoinvent and EXIOBASE among them. It holds factors and no company records: a factor exists for a sector in a region, never for a named supplier, so every figure it returns for a Category 1 line is secondary data, and a large factor count is the size of a shared resource rather than of anything Climatiq holds. DitchCarbon's own generic layer draws on the same databases; the difference is that on a DitchCarbon baseline that layer is reached fourth of four, only where the supplier's own inventory, a product footprint and activity data could not be found. We checked Climatiq for our verification benchmark and found no public software-level verification.

What you still need afterwards: the company-specific layer entirely. A factor API produces secondary data for every line, so the primary share of the baseline, the number CSRD and CDP ask you to state, is zero until another source supplies it.

Verification status from our benchmark, Who's Really Verified? A Reality Check on Carbon Software Assurance, evidence links last checked 19 August 2026. "Not in our benchmark" means we have not checked that vendor and nothing should be read into it.

Which emission factor databases matter in 2026?

Five sources sit underneath most of the market. Worth knowing which ones you are already paying for twice, inside different tools. Aggregators such as Climatiq resell these same sources through a single API, so a large headline factor count usually describes someone else's data.

Table compiled August 2026 from each publisher's own documentation.

Two things are worth noticing. Three of these five now sit under one commercial roof: Watershed owns CEDA outright and, through Cornerstone, co-stewards USEEIO and the US emission factors hub. A shortlist that treats CEDA and USEEIO as independent options is out of date. And EXIOBASE's newest firm year is 2020, which is a long time ago for a spend factor.

DitchCarbon's own generic layer draws on ecoinvent, CEDA, EPA, DEFRA and EXIOBASE. So does almost everyone else's, in some combination. Factor library size is table stakes, and a vendor quoting the size of its library is quoting the size of a shared resource.

How do the company emissions databases compare in detail?

This is the category most buyers are looking for when they say supplier emissions data, and it is the smallest. It is also worth asking what a provider does once the figure exists, because a company record on its own is a lookup: whether it carries history and restatements, a benchmark, a forward view against the organisation's own target, and a route from the number to a decision.

Table compiled August 2026 from each vendor's public documentation. Capabilities change, so check the current position with any vendor before a decision.

Which collection platforms and accounting tools should be on the list?

Both remaining categories are well served, and neither is a data source.

Collection platforms: EcoVadis for supplier ratings and carbon maturity, IntegrityNext, Assent, Sphera (formerly SupplyShift), Sedex for labour and ethics audits, CDP Supply Chain for structured disclosure requests, and Novata for private markets. What they share is that a supplier who does not answer produces no data. DitchCarbon also sits in this group, and the difference is how often the request is needed at all. Running collection on top of a company database means most suppliers already carry a figure, so the ask goes only where it changes the number. Where one does go out it arrives prepopulated with what that organisation has already published, so the supplier reviews and corrects rather than compiles, which gets a higher response rate than a cold survey. That is worth stating in a category built on surveys: a supplier's sustainability team is usually one or two people, and every buyer running its own programme asks them the same questions in a slightly different order.

Carbon accounting platforms: Watershed, Persefoni, Sweep, Normative, carbmee, CO2 AI and Greenly. What they share is a calculation engine, a reporting layer and, for Category 1, a fallback to spend factors when company-specific data is not supplied to them.

Neither group is a weaker choice than a data provider. They answer different questions, and a mature programme usually runs one of each. A few providers span two categories, which is worth checking rather than assuming from how a vendor describes itself.

Do CSRD or the GHG Protocol require supplier-specific data?

No. Neither obliges you to use supplier-specific data for Category 1. Both oblige you to disclose how much of it you used.

The GHG Protocol Scope 3 Standard says companies should use primary data collected from suppliers for activities targeted for reductions, and it is explicit that secondary data may be of higher quality than the available primary data for a given activity. What it requires is different: companies are required to report the percentage of emissions calculated using data obtained from suppliers or other value chain partners. The Category 1 guidance is equally clear that companies need not always use the most specific method as a first preference.

ESRS E1 works the same way. Application requirement 46 opens with the undertaking shall, and the relevant sub-paragraph requires you to disclose the percentage of emissions calculated using primary data obtained from suppliers or other value chain partners. Note what the obligation attaches to. It is disclosing the percentage, not achieving one. There is no threshold and no minimum primary-data share anywhere in E1.

So every framework asks you to say how much supplier-specific data you used. None of them tells you to have any. The obligation is to be able to answer the question, which makes this a data availability problem rather than a compliance one.

Two dates worth carrying. The revised ESRS were adopted on 3 July 2026 and apply to financial years beginning on or after 1 January 2027, with the disclosure requirement renumbered from E1-6 to E1-8. And the value chain cap, which limits what large companies can demand from smaller suppliers, explicitly does not cover gross Scope 1, 2 and 3 emissions.

How many companies actually disclose their emissions?

Nobody knows, and it is worth being honest about that. Every figure in circulation describes a listed equity index, not the population of companies in the world, and no credible global denominator is published.

Inside the listed universe the numbers are still sobering. MSCI examined 8,197 companies in its All Country World Investable Market Index and found that only 13% reported on their most material Scope 3 categories. CDP reports that over 22,100 companies disclosed environmental data through it in 2025, which is a count rather than a share.

Two published figures for Scope 1 and 2 disclosure in 2023 look irreconcilable until you check the universes. One gives nearly 60% and the other nearly 80%, for the same year, because one covers around 8,200 companies including small caps and the other around 2,700 large and mid caps. Small caps disclose far less. Below the listed universe, where the great majority of any company's suppliers sit, the rate is unmeasured and certainly lower again.

Which is the whole argument for this category existing. If most suppliers disclosed, a spreadsheet would do.

Which providers publish independent verification of their methodology?

Very few, and the distinctions matter. Verification of a vendor's own calculation is not an auditor assuring your inventory, and neither is a security certification such as SOC 2 or ISO 27001.

DitchCarbon is the only specialist Scope 3 tool with third-party assurance of its calculation methodology, and was the first company to earn UL Solutions' Sustainability Information Calculator Verification, in June 2025. The full working, including every vendor checked and the evidence for each, is in our benchmark, Who's really verified? A reality check on carbon software assurance. The underlying documents are downloadable from the DitchCarbon trust centre.

Ask any provider for the declaration itself, not a page that says audit-ready. Audit-ready without a named verifier and a named standard is marketing.

What if you are the supplier being asked?

Most companies reading a page like this are on both sides of the request. You are measuring your own suppliers, and your customers or investors are asking you for the same thing. If that is you, claiming your DitchCarbon profile lets you answer once and reuse it, including work you have already done for CDP or an EcoVadis assessment. It is free and self-serve. Claim your profile.

How do you choose between them?

Start by naming which of the four categories you actually need, because that removes most of the market in one step. Then run the same test on every provider left standing. Send a real sample of your own suppliers, not a curated one, and ask how many they hold a company-specific figure for today, where each figure came from, and what happens to the rest.

DitchCarbon will show you what it already holds on your list, with the source and change history behind every figure. Numbers you can defend within 2 weeks.

Provider list updated 22 September 2026. Last full review August 2026.