Supplier emissions data providers compared, 2026

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

This page sorts the market into those four groups, says what each is genuinely for, and gives the current state of the main options in each 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 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 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.

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.

Which company emissions databases actually hold a figure per company?

This is the category most buyers are looking for when they say supplier emissions data, and it is the smallest.

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.

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.

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.

Last reviewed August 2026.