CDP verification requirements 2026: accepted standards, coverage thresholds and what a verifier checks

CDP verification means third-party assurance of your reported emissions against a standard on CDP's accepted list, evidenced by a verification statement attached to your response. For Leadership you need at least 95% of reported Scope 1 and 95% of reported Scope 2 verified plus at least one Scope 3 category. For the A List you need 100% of Scope 1, 100% of Scope 2 and at least 70% of reported Scope 3. ISO 14064-3 and ISAE 3000 are the two standards most companies use, and both are accepted including their national variants.

Last updated August 2026. Verification is the criterion that decides more CDP scores than any other, and it is the one you cannot fix in the weeks before the deadline. It needs a provider engaged, a scope agreed, records sampled and a statement issued, all before September 16. Below: which standards CDP accepts, what the coverage thresholds actually mean, what a verifier looks at, what changed in the 2026 questionnaire, and how to tell now whether you will clear the bar.

What is CDP verification?

Verification is an independent check, performed by a third party you engage and pay, that the emissions figures you are reporting are materially correct and were produced by a defensible process. CDP does not verify anything itself and does not accredit verifiers directly. It publishes a list of verification standards it accepts, requires that your provider be accredited under internationally recognized standards, and asks you to attach the resulting statement to your response.

The distinction that trips people up is between verification and validation. Verification looks backwards at emissions that have already occurred and asks whether the reported figure is right. Validation looks forwards at a target or a plan and asks whether the approach is sound. The Science Based Targets initiative validates targets. An assurance provider verifies inventories. CDP asks for the second, and having the first does not substitute.

The reason CDP weights this so heavily is straightforward. Every other answer in the questionnaire is a claim you make about yourself. Verification is the only place a third party puts its name to your numbers, so it is the single point where CDP can distinguish a well-written response from an accurate one. Verification (including emissions) carries 10% of the Leadership score as a scoring category, on top of being a pass or fail essential criterion.

Which verification standards does CDP accept?

CDP maintains two published lists, accepted standards and not accepted standards, and the accepted list runs to more than fifty entries. Most of them are national or scheme-specific. In practice, US companies land on one of a small handful.

The list above is the part of CDP's accepted list most US companies will use, not the whole of it. CDP also accepts a long tail of national and provider-specific standards, and it updates both lists, so check the current version before you sign an engagement letter rather than after. The criteria CDP applies when deciding whether to accept a standard are worth knowing because they tell you what it cares about: third-party performance of the audit, verifier competency, a requirement that ensures impartiality is maintained, clear terminology, documented methodology, and public availability of the standard.

Impartiality is the one that catches companies out commercially. A firm that built your inventory generally cannot then assure it, because the independence requirement inside these standards bars self-review. If a consultancy has been calculating your footprint for three years, budget for a different firm to verify it. The practical differences between the levels of assurance you can buy are covered in limited vs reasonable assurance for emissions.

How much of your emissions does CDP require you to verify?

The thresholds are set by essential criterion EC-CC17 and they are percentages of reported emissions, not percentages of facilities or of spend.

Two things follow from reading that table carefully. The Scope 3 requirement is where the two rows genuinely diverge: one verified category is a manageable add-on to an existing engagement, while 70% of reported Scope 3 usually means verifying purchased goods and services, which is the category with the weakest data in most inventories. That gap explains a lot of A- scores. And because the thresholds are percentages of what you report, they interact with completeness in a way that is easy to misread. Reporting fewer Scope 3 categories does not make the 70% easier in any useful sense, because an incomplete screening fails a different criterion.

That second point is the dependency worth committing to memory. EC-CC15, the Scope 3 disclosure criterion, is a stated pre-requisite for EC-CC17. If your screening across the fifteen categories is incomplete, you fail EC-CC15, and failing EC-CC15 cancels the Leadership credit for verification you have already paid for. Companies discover this after the invoice. How the screening is supposed to work is in CDP Scope 3 relevance, and the categories themselves are on the 15 Scope 3 categories.

What changed for CDP verification in 2026?

Three changes, all in the same direction. CDP made full Disclosure points on the verification questions a pre-requisite, so an incomplete answer on the verification questions themselves now removes credit rather than reducing it. It added a route for organizations reporting no verification, which sounds generous and mostly serves to make the absence explicit and scored. And it added a new column capturing the proportion of total reported Scope 3 emissions verified as a percentage, checked at Leadership.

That third change is the substantive one. Until this cycle you could report that a Scope 3 category had been verified without CDP knowing what share of your value chain emissions that represented. A company verifying business travel, a category that might be 1% of its footprint, filed the same answer as a company verifying purchased goods and services. Now the percentage is on the form. The full set of question-level changes for this cycle is on CDP 2026 changes.

What does a CDP verifier actually check?

Not your arithmetic, mostly. A verifier assumes you can multiply and spends the engagement testing whether the numbers can be traced and whether the process that produced them is sound. In practice an engagement moves through the same sequence every time.

1. Boundary and scope. Does the reported organizational boundary match the consolidation approach you claim, and does it match your financial reporting entity list? Whether you use operational or financial control changes which sites are in, and the choice is covered in operational vs financial control.
2. Completeness. Are there sites, meters, vehicles or fuel types missing from the inventory that appear in your property schedule, fleet list or accounts payable ledger? This is where most findings originate.
3. Sampling back to source. The verifier selects individual figures and asks for the document behind them: the utility bill, the fuel invoice, the meter reading, the supplier statement. The test is whether a number in your inventory resolves to a specific record.
4. Emission factors. Which factor set, which vintage, which global warming potentials, and are they applied consistently? Mixing AR5 and AR6 potentials in one inventory is a standard finding, and factor choice is covered in which EPA emission factors to use.
5. Recalculation. A subset of figures is recomputed independently and compared against yours, with a materiality threshold agreed in advance.
6. Controls and process. Who enters the data, who reviews it, what happens when an estimate is used, and is the estimation method documented rather than remembered.

Step three is where spreadsheet inventories fail, and they fail on evidence rather than on accuracy. The tonnes are frequently right. What does not exist is the trail from a total back to the twelve bills that produced it, because somewhere in the chain a person typed a number into a cell from a PDF and the link was lost. Building the inventory by reading the underlying bills and invoices directly rather than rekeying totals is what makes a sampled figure resolvable months later, and it is the difference between a clean engagement and a list of findings. What an auditor looks for in general is set out in what a carbon audit is.

How long does CDP verification take and when should you start?

Plan on three to six months from first contact to a signed statement for a first engagement, and six to ten weeks for a repeat engagement with a provider who already knows your estimation methods. The long pole is rarely the fieldwork. It is scoping and contracting, then the back and forth when the verifier asks for evidence that has to be retrieved from someone else's inbox.

Against the September 16, 2026 scoring deadline, that means a first verification started in August is not going to be complete, and the honest move is to report accurately for this cycle and start the engagement now for next. There is a partial answer for companies mid-engagement: CDP allows you to report that third-party verification or assurance is underway with last year's statement attached, provided the documentation is no earlier than two years prior to the current reporting year. That is a real option, not a workaround, but it is not equivalent to a current statement and should not be planned for twice.

The full 2026 calendar, including the paid extension that moves the scoring deadline to September 30, is on the CDP reporting deadline for 2026.

How to know now whether you will clear the verification bar

1. Express your current verified coverage as a percentage of reported emissions for Scope 1, for Scope 2 and for Scope 3, separately. Not as a list of what was assured. If you cannot produce those three percentages in an afternoon, that is itself the answer.
2. Check your provider's standard against CDP's accepted list, and check that the statement covers the reporting year you are disclosing.
3. Confirm the verifier is not the firm that built the inventory.
4. Confirm your Scope 3 screening covers all fifteen categories, because EC-CC15 gates EC-CC17 regardless of how much you verified.
5. If you are targeting the A List, work out which Scope 3 categories get you past 70% of reported emissions, and price verifying those specifically. It is usually one or two categories, not seven.

Step one is the diagnostic. Companies that can answer it immediately are usually fine. Companies that need a week to reconstruct it have an evidence problem rather than a coverage problem, and evidence problems repeat every cycle until the way the inventory is built changes. That is the ground our carbon accounting software is built on: classifying accounts payable and utility records into a scope by scope inventory where every figure stays attached to the document that produced it. The full A List gate list, including where verification sits among the other seven criteria, is on CDP A List criteria.

This article summarizes CDP's published verification guidance and accepted standards list, the CDP Climate Change Scoring Essential Criteria 2026 and the CDP Full Corporate Scoring Changes 2026, as they stood in August 2026. CDP updates its accepted and not accepted standards lists and describes its 2026 criteria as provisional, so check the current versions and the exact scored data points against CDP's own documents before you engage a provider or submit. Engagement timelines are typical ranges, not commitments. Nothing here is legal, accounting or assurance advice, and this article is not affiliated with or endorsed by CDP.