CO₂ Performance Ladder levels: why there are now three steps, not five levels

What are the levels of the CO₂ Performance Ladder in 2026?

There are no levels any more. SKAO, the scheme owner, published handbook 4.0 on 14 January 2025 and describes the change on its own page as "vervanging van vijf niveaus door drie treden met hoger ambitieniveau", the replacement of five levels by three steps with a higher ambition level (SKAO, Wat is de Ladder). The English explainer is blunter: the five levels from version 3.1 no longer exist and are replaced by these three steps (SKAO, These are the three steps of version 4.0).

Old levels 1 and 2 were deleted. Level 3, for years the de facto market minimum, became the new entry point and is now called step 1. Certification against 4.0 has been possible since 14 July 2025. Any audit after 14 January 2027 has to be a 4.0 audit.

Both models are in circulation at the same time. Some tenders still reference 3.1 and some already reference 4.0. SKAO's transition rules put an end date on that: "Dit betekent dat er tot 14 januari 2028 nog geldige certificaten voor Handboek 3.1 kunnen zijn (36 maanden na de publicatiedatum van Handboek 4.0)", meaning valid 3.1 certificates can exist until 14 January 2028, 36 months after handbook 4.0 was published (Transition rules 3.1 to 4.0, pdf).

The affected population is large. Around 8,000 organisations hold a certificate and more than 300 public contracting authorities use the Ladder in their procurement. Roughly three quarters of certificate holders are small and medium-sized enterprises; SKAO's own page puts it at "more than two thirds". These are mostly organisations without a standards department, doing the migration alongside the day job.

What is the CO₂ Performance Ladder for, if you have never met it?

Most people outside the Netherlands and Belgium meet the Ladder because a client or a tender document mentions it. It does two jobs at once. It is a carbon management system, comparable in spirit to an ISO management standard, and it is a procurement instrument.

The procurement part is the reason anyone gets certified. Dutch and Flemish contracting authorities award a gunningvoordeel, a tender advantage, to bidders who hold a certificate. The usual mechanism is a fictieve korting, a notional discount: your bid price is reduced on paper for evaluation purposes only. If you win, you are paid the price you actually quoted. A bid of 30 million euro at a 4 percent advantage is evaluated as 28.8 million, which can beat an uncertified bid of 29 million, and the winner still invoices 30 million.

Two rules matter before you plan around it. A certificate may not be used as a suitability requirement, only as an award criterion, and you do not need to hold a certificate to bid. Bidders declare an ambition level and then have to demonstrate it, by certificate or by a project-specific statement (projectverklaring), within a year of award. The full mechanism, including the legal limits and the sanctions for not achieving the declared level, is in the piece on tender advantage with the CO₂ Performance Ladder.

Why does the word step or level matter?

A complaint circulates among certificate holders that sounds small and is not. One sustainability lead put it this way: "We have an auditor who is really allergic when you use step instead of level." In other audits exactly the reverse happens.

The word is a tell. If you still talk about levels inside a 4.0 project, you are showing that nobody has properly read the new handbook. The other way round, using the word step during a live 3.1 project suggests something has been delivered that has not.

The practical rule: say level while your certificate is on 3.1, say step from the moment you enter the initial 4.0 audit, and put the version number in every ambition document. Without that version number, "level 3" is an ambiguous statement in 2026.

How do the three steps in handbook 4.0 work?

Step 1

Step 1 is about your own organisation. You produce an energy review and an emissions inventory for scope 1 and scope 2, you write an action plan with a list of measures, and you report on progress at least once a year.

Three things are genuinely new (SKAO, all about step 1). You have to name key personnel responsible for CO₂ awareness: the people who decide on procurement, fleet or building management and therefore actually drive emissions. You have to set energy saving as an explicit objective, because cutting CO₂ does not automatically cut energy use. And you have to include non-CO₂ greenhouse gases where relevant, so methane, nitrous oxide and refrigerants, converted to CO₂ equivalents.

Some things also disappeared. Mandatory participation in a sector initiative is gone, business travel reporting is no longer compulsory at step 1, and where 3.1 expected a footprint twice a year, SKAO says that in 4.0 once a year can be enough.

Step 2

Step 2 extends the boundary to the value chain. That means scope 3, limited to the part where you can make the most difference. You start with an impact and influence analysis, requirement 2.A.4 in the handbook: where the emissions sit and where you genuinely have a say. From that follow a value chain analysis, requirement 2.A.5, and a climate transition plan with targets, requirement 2.B.1, looking five to ten years ahead (Handbook 4.0 step 3, pdf).

This is also where OBE appears, the overige beïnvloedbare emissies or other influenceable emissions. These are emissions outside your own scopes that you can still influence, for example by building with recycled material or sharing energy with a neighbouring company on the same site. At step 2 this may stay qualitative.

Organisations with more than 250 employees get one extra requirement. SKAO writes that the climate transition plan "moet worden afgestemd met een onafhankelijke deskundige en in het kader van samenwerking twee keer per jaar moet worden besproken met een ketenpartner. Dit moet telkens een andere partner zijn": it has to be aligned with an independent expert and discussed twice a year with a value chain partner, and it has to be a different partner each time (SKAO, all about steps 2 and 3). Two conversations a year with the same partner do not satisfy it.

If you have no idea where to start, SKAO publishes an open register of over 1,200 chain analyses written by other certificate holders, of which material use under scope 3 is the largest theme at 440 documents (count taken 11 August 2026). Right now that register is the closest thing to a sector template.

Step 3

Step 3 asks for an end point: zero emissions in 2050 across scope 1, 2 and 3. The difference with step 2 is reach. SKAO puts it this way: at step 2 you may limit yourself to the emissions of your most important activities, while at step 3 you have to address every activity you can influence. Reduction has to be demonstrated in numbers, inside your own organisation, in the chain and for OBE.

SKAO itself calls scope 3 at this level very demanding. Step 3 needs data from chain partners who often do not have that data themselves, which makes it a data collection problem before it is a calculation problem.

What changed structurally between 3.1 and 4.0?

The change goes beyond the number of ambition steps. The shape of the document is different too, and you notice that as soon as you start writing.

The names of the four angles, the split into part 1 and part 2 and the requirement code format can all be checked in the handbook 4.0 for step 1 (pdf), which states: "De indeling in deel 1 volgt de ISO-Harmonized Structure (HS)."

Two of these cause most of the confusion in practice.

First the angles. Letters A to D remain, but C and D were renamed. Transparency became Communication, Participation became Collaboration. Your existing communication plan is not worthless, but the requirement around it has shifted and the auditor tests against the new wording.

Second the numbering. It looks identical and counts differently. In 3.1 the first digit refers to the level, in 4.0 to the step. A reference to "3.A.1" therefore means something completely different in 3.1 than in 4.0. In internal documents that survive the transition this is a quiet source of errors, especially in quality manuals where requirement codes are used as cross-references.

Part 1 of each 4.0 handbook is identical for all three steps and covers the organisational boundary, the CO₂ management system and documentation, among other things. For groups with multiple entities part 1 is the hardest part, and the piece on organisational boundaries across multiple entities goes into that.

Which step matches my current level?

This is where you have to pay attention, because SKAO answers this question in four places and not in quite the same way.

All four sources agree on two things: step 1 sits at the height of old level 3, and step 2 sits at the height of old level 5. They diverge on two others. Only the FAQ states in so many words that step 1 formally covers old levels 1 and 2 as well. And on step 3 they contradict each other: the transition rules and the procurement blog equate step 3 with level 5, while the certification page says step 3 goes further than any level of version 3.1. For your tender that makes no difference, because the acceptance rule is at least level 5 in every version. For your planning it does: if you are jumping to step 3, do not budget for the size of an old level 5 file.

What happens to level 4?

No step sits at the height of old level 4. In procurement terms that is covered, because SKAO's FAQ accepts a certificate at step 2 or step 3 as a certificate for levels 4 and 5. What is missing is the sideways move.

If you are certified at level 4 today, you either drop to step 1 in formal recognition or you make the jump to step 2, which adds a mandatory climate transition plan and a value chain analysis. For this group it is the hardest decision in the whole transition. Which documents carry over and which have to be rewritten is worked out in the migration guide from 3.1 to 4.0.

Watch the audit type as well. SKAO writes: "een 4.0-audit voor trede 2 is altijd een initiële audit, ook als u al gecertificeerd was op niveau 5", and separately: "Een 4.0-audit voor trede 3 is altijd een initiële audit". A 4.0 audit for step 2 and for step 3 is always an initial audit, even if you were already certified at level 5 (From handbook 3.1 to version 4.0). That means more audit days than a routine surveillance audit, including for organisations that have sat at the top level for years. What that costs is set out in the cost of the CO₂ Performance Ladder.

Does my certificate count in the other version?

The asymmetry has commercial consequences. A 4.0 certificate works in both worlds, a 3.1 certificate will soon work in only one. If you bid often over the next two years, switching buys you flexibility as well as compliance.

What were the five levels of handbook 3.1?

This table is historical. Handbook 3.1 still applies to certificates already issued and to tenders that explicitly reference it, but no 3.1 audit can take place after 14 January 2027.

The four angles in 3.1 were Insight, Reduction, Transparency and Participation. Each higher level included the ones below it.

Level 3 was the market minimum in practice, because it was the first step with a full footprint conforming to ISO 14064-1 and the GHG Protocol. That makes it understandable that the entry point of 4.0 sits exactly there, although SKAO does not motivate the choice in those terms anywhere.

Why does everything online still say five levels?

Because most explainer pages predate January 2025 and were never rewritten. We looked at the results on the core queries in August 2026: several pages that rank at the top still describe five ambition steps, with a recent date stamp underneath. Ask a language model today and you will often get the same outdated answer back. That is our own observation rather than a measurement by SKAO, but it takes five minutes to reproduce.

There is a practical reason too. The old model is not dead. Few contractors have completed the switch, so there are almost no reference implementations to copy and sector templates do not exist. As one practitioner said: "We now generate our own format. But I am not sure if it is in line with what the auditor expects."

That is exactly the phase in which outdated explanations survive longest. Everyone cites what is there, and what is there is no longer correct. So check every source you read for a date after January 2025 and for the word trede.

Which step should I aim for?

For most organisations the answer follows from the tenders they bid on. You aim for the step your clients reward.

SKAO says so explicitly: "Welk percentage, bedrag of puntenaantal u als gunningsvoordeel kiest, bepaalt u zelf", meaning each authority decides the percentage, amount or points itself. There is no national tariff and you have to check per client. If you work for Flemish authorities, look at the Belgian situation, which runs on its own timeline. If the Ladder is new to your country entirely, start with the international guide to the Ladder.

Outside construction and civil engineering the choice is harder, because SKAO's worked examples and the mandatory emission factors are shaped around those sectors. What that means for IT, healthcare, logistics and manufacturing is in the CO₂ Performance Ladder outside construction. If you are a smaller organisation that also has to produce a VSME report, Step 1 overlaps with a large part of it: see the CO₂ Performance Ladder and VSME.

Three rules of thumb that hold up in practice:

• If you mainly bid on work that asked for level 3, step 1 is your target.
• If level 5 was asked for, step 2 is the minimum and step 3 is a deliberate differentiation choice.
• If you sit at level 4 there is no neutral option, and you have to weigh the loss of tender advantage against the cost of jumping to step 2.

One argument stands apart from procurement. SKAO's FAQ refers to research in which certified organisations achieved CO₂ reductions of 3.2 percent a year against a national energy saving rate of 1.5 percent a year. That research covers the period 2010 to 2013, so treat it as an indication rather than a current figure.

When do you have to switch?

Count back from your own audit date, not from 14 January 2027. An audit in March 2027 means writing starts in autumn 2026. Allow for the summer period as well: the familiar situation where one person is away, then the other is out for three weeks, and the first real conversation happens at the end of August, costs a preparation project most of the summer.

The trap is that the migration looks manageable from a distance. As one sustainability lead summarised it: "We are ready to do the audit following the 3.1 handbook, but we do not have the new demands in the handbook." Most of the work carries over. What does not carry over only becomes visible when you go looking for it, and that is usually the moment the audit date is already fixed. Which parts auditors send back in practice is covered in what auditors reject.

Is there going to be a step 4?

Step 4 is in development. In a blog post dated 19 February 2025 SKAO wrote that this step would be introduced "op z'n vroegst pas in 2026", in 2026 at the earliest, after a co-creation process running through 2025. SKAO added that because step 4 will initially be within reach of only a few organisations, it will not be taken up as an award criterion in tenders immediately after its introduction. As of mid 2026 no introduction date has been announced. The requirements are not fixed, so do not base a certification plan on it and do not assume it in tender documents.

How Palau handles this

In Palau the CO₂ Performance Ladder sits as its own framework alongside CSRD, VSME and EcoVadis, so you report against it without setting up a second administration. Evidence lives in Vault, attached to the data point it belongs to, so an auditor can follow the trail back from a statement to its source. That same data point is available through Reef for your CSRD reporting, without a second data request to the same people. A shorter introduction to the Ladder sits on our CO₂ Performance Ladder solution page.

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Frequently asked questions

Does the CO₂ Performance Ladder have three steps or five levels? Three steps, since handbook 4.0 of 14 January 2025. The five levels belong to handbook 3.1. Under SKAO's transition rules, valid 3.1 certificates can exist until 14 January 2028.

Which step corresponds to level 3? Step 1. SKAO accepts a 4.0 certificate at step 1 as evidence for CO₂ ambition level 3 in a tender still written against 3.1.

What happens to level 4? No step sits at the height of level 4. For tenders it is covered: the FAQ accepts a certificate at step 2 or step 3 as a certificate for levels 4 and 5. Organisations at level 4 therefore choose between step 1 and step 2.

Is my 3.1 certificate valid in a 4.0 tender? No. The reverse does hold: a 4.0 certificate is valid in a 3.1 tender.

When is my last chance at a 3.1 audit? 14 January 2027. At your first audit after that date you move to 4.0 permanently.

Is a 4.0 audit a surveillance audit or an initial audit? For step 2 and step 3 it is always an initial audit according to SKAO, even if you were already certified at level 5.