In short
- ProRail turns your declared CO2 ambition level into a fictitious discount on the bid price, which it says can run up to 10 percent.
- You produce a declaration at bid time and proof during execution, either project-specific evidence or a matching CO2-bewust certificate.
- What a step up is worth is the increment. In ProRail's provisional 4, 7 and 10 percent staffel that is 3 percentage points, not the headline number.
ProRail scores the CO2-Prestatieladder as a project-related subcriterion: you declare the CO2 ambition level you will execute the contract at, and ProRail applies a fictieve korting, a fictitious discount, to your bid price for ranking purposes. The higher the level, the larger the discount, and ProRail says it can run up to 10 percent across virtually all of its tenders. You produce nothing at bid time beyond the declaration. The proof comes during execution, and the level you named becomes a condition of the contract you signed.
How does the scoring actually work?
Three moves, in this order.
At bid. The ambition levels appear in the tender documents as project-related subcriteria. You state the level at which the contract will be executed. No certificate is required to do this, and there is no published minimum level as a suitability requirement.
At evaluation. ProRail converts the declared level into a fictitious reduction of your bid sum. The money is notional: it exists only to rank bids against one another and the contract price does not change. A bidder one level above you at an identical price is effectively cheaper on the ranking by the difference between the two reductions.
At award and after. The subcriteria become contract conditions. ProRail then checks during execution whether the level you offered is actually being delivered.
What do you have to produce, and when?
A declaration first, evidence later, and the evidence has two accepted routes.
| Stage | What you produce | Who is involved |
|---|---|---|
| Submission | A stated CO2 ambition level for this contract. No certificate | Your bid team |
| Award | Nothing new. The declared level becomes part of the contract | ProRail |
| Execution, within the agreed period | Either project-specific evidence for this contract, or a CO2-bewust certificate matching the level you offered | A certificerende instelling, a certifying body, has a role in both routes |
The two routes are not equivalent in effort or in reuse. A certificate is organisational: it costs more to obtain, it is audited annually, and it serves every bid you make while it is valid. Project-specific evidence is narrower, tied to this contract, and does not carry across to the next tender. If you bid to ProRail regularly, the certificate route amortises and the project route does not. If this is a one-off contract in a market you do not otherwise serve, the reverse can be true.
ProRail confirms the no-certificate-at-bid position continues after its switch to Handboek 4.0 from 1 January 2027, so this part of the mechanism is stable across the version change.
What is a level actually worth?
Under the provisional staffel ProRail has published for version 4.0, this is the arithmetic that matters.
| CO2-ambitieniveau | Provisional fictitious reduction of the bid sum | Increment over the level below | What the level rests on |
|---|---|---|---|
| No level declared | None | Not applicable | Nothing. A valid bid that earns nothing here |
| Trede 1 | 4 percent | 4 points, against declaring nothing | Scope 1 and 2 emissions |
| Trede 2 | 7 percent | 3 points | Quantified scope 3 and a klimaattransitieplan, a climate transition plan |
| Trede 3 | 10 percent | 3 points | A quantified route to zero emissions by 2050 |
Two things fall straight out of that table.
The first is that the biggest single step is the first one. Going from no declared level to trede 1 is worth 4 points on the ranking under this staffel, and the underlying work is your own scope 1 and 2 emissions, which is the most tractable data you have. Every step after that is worth 3 points and costs considerably more.
The second is that the headline number is not what you gain. If you already sit at trede 2, moving to trede 3 is worth 3 percentage points on the ranking of a bid, not 10. Any business case built on the full 10 percent is overstating the return by more than three times.
Treat the percentages themselves as provisional, because ProRail does. Its wording is voorlopig and, in SKAO's report of the announcement, voorgenomen, and it states that a different weighting can apply to some tenders. ProRail publishes no per-level staffel at all for the five niveaus it uses today, only the up-to-10-percent ceiling.
What happens if you do not deliver the level you offered?
ProRail publishes that it checks realisation of the offered ambition level during execution. What it does not publish, at least in the sources verified here, is a sanction amount or formula.
That is worth stating plainly rather than filling the gap with a figure from elsewhere. Rijkswaterstaat publishes a multiplier of 1.5 times the fictitious advantage enjoyed; that is Rijkswaterstaat's number and it is not ProRail's. The consequence for your bid modelling is that the downside of over-declaring at ProRail is defined by the contract you are about to sign, not by anything you can look up in advance. Read it there.
The safer framing: the declared level is a promise about how you will execute, checked by somebody who has the contract in front of them. Declare a level you have a credible plan to evidence, not the one that maximises the ranking.
Which version is this tender running on?
The publication date of the procurement decides, and both versions will be in play for a while.
For tenders started before 1 January 2027 where the Ladder is an award criterion, version 3.1 remains the basis and a version 4.0 certificate is accepted as proof under ProRail's own equivalence: trede 1 counts as niveaus 1, 2 and 3, and treden 2 and 3 count as niveaus 4 and 5. ProRail applies the same equivalence to running contracts, because a contractor can end up holding only a 4.0 certificate part way through a ProRail contract once 3.1 audits stop on 14 January 2027.
From 1 January 2027 ProRail intends to use Handboek 4.0 in all newly published TenderNed procurements where the Ladder is an award criterion. And in all cases ProRail states that its tender documents on TenderNed, not its website, are decisive for the exact arrangement applied.
How should you choose the level you declare?
Four numbers, in this order.
The increment, applied to the bid sum, not the headline percentage. Your win margin, because a ranking advantage only converts into revenue on bids you would otherwise lose narrowly. The cost of the underlying work, which rises steeply between trede 1 and trede 2 because quantified scope 3 is a supply chain data exercise on other people's timetables. Your exposure across every contract you declare it on, since the same level named in five bids becomes five contract conditions.
There is a legitimate strategy in declaring a level you do not yet hold, because ProRail does not check at bid time. It is only legitimate if the accounting system that proves it can realistically exist inside the delivery window. That is a scheduling judgement, and it is the one most often made optimistically.
What does the evidence have to survive?
Being followed backwards. Whichever proof route you take, a certifying body is involved, and the working standard is that individual figures can be traced to source rather than that the total looks reasonable.
The Hedgehog platform names the CO2-Prestatieladder among its reporting outputs, carries over 20,000 spend-based and activity-based factors that you can supplement with your own supplier-specific data, and reports 5,000+ users on its platform page. One limitation to weigh if you are modelling a declaration across a multi-year contract: a small business reviewer on G2 in August 2026 rated it 5 out of 5 and noted there is no forecasting today, with Hedgehog having told them it is on the development list. Projecting what a declared level costs you over the life of a contract is currently work you do outside the tool.
Where quantified scope 3 stands between you and trede 2, that is scope 3 consulting with a long calendar rather than a bid-week task, and scoping the trede decision itself sits with carbon footprint consulting. Our introduction to the CO2-Prestatieladder for SMEs covers the scheme behind the criterion.
Sources: ProRail supplier page on the CO2-Prestatieladder, SKAO news item of 4 June 2026 reporting ProRail's announcement, Hedgehog platform, Hedgehog on G2. Verified 18 September 2026.
Facts on this page were last verified on 2026-09-18.
