Handbook 4.0 of the CO₂ Performance Ladder is a complete overhaul. It is more demanding, better aligned with European standards, and now rewards actual results, not just stated intentions.
major changes compared to the previous handbook
first step where full scope 3 is required
net zero target required from Step 3 onwards
deadline for transition to Handbook 4.0
The 3 steps of Handbook 4.0
Requirements are assessed against 4 axes at the annual audit. Items in bold are new or strengthened under Handbook 4.0.
Insight
Reduction
Transparency
Participation
Insight
Reduction
Transparency
Participation
Insight
Reduction
Transparency
Participation
Indicates a requirement that is new or strengthened under Handbook 4.0.
Handbook equivalence
Terms changed between the two handbooks. This table helps you map the old system to the new one, particularly useful for tenders during the transition period.
| Handbook 4.0 (steps) | Handbook 3.1 (CO₂ Ambition levels) | Main scope |
|---|---|---|
| Step 1 | Levels 1, 2 and 3 | CO₂ reduction within your own organisation |
| Step 2 | Levels 4 and 5 | CO₂ reduction across the value chain |
| Step 3 | Levels 4 and 5 | CO₂ reduction towards net zero by 2050 |
Source: CO₂ Performance Ladder Procurement Guide 4.0 (SKAO). Certifications based on Handbook 3.1 cannot be used to demonstrate compliance with Handbook 4.0 award criteria.
The 6 key changes
Six structural changes that redefine what a CO₂ Performance Ladder certification actually requires from your organisation.
Stating ambitions is no longer enough. Certified organisations must now prove they are actually meeting their reduction targets, not just that they have planned them. The audit checks real results.
The inventory must cover all 15 categories of indirect emissions from the GHG Protocol (upstream and downstream). At least two thirds of total value chain emissions must be covered and documented.
If Other Influenceable Emissions (OIE) — biogenic emissions, CO₂ removals and avoided emissions — are relevant to your organisation, they must be analysed and integrated into the transition plan targets. This was not required in the previous handbook.
A formal climate transition plan is now required with a net zero target by 2050 for scopes 1, 2 and 3, and an intermediate target over 5 to 10 years. Previously, this was only required at Step 3.
Value chain analysis already existed in the previous handbook. Handbook 4.0 deepens it with a new Influence and Impact (I&I) matrix that structures the analysis by main activity, both upstream and downstream, with a higher level of detail.
Reduction targets must be compatible with a net zero objective by 2050, or validated by the Science Based Targets initiative (SBTi). Alignment is no longer optional at Step 3.
Before / After
A clear overview of the requirements that have evolved between the old and the new handbook.
| Axis | Handbook 3.1 | Handbook 4.0New |
|---|---|---|
| Results | Planned ambitions and targets were sufficient | Prove that targets are actually met at the annual audit |
| Scope 3 | Partial coverage of indirect emissions | All 15 GHG Protocol categories required from Step 2, with at least 2/3 of emissions covered |
| Other Influenceable Emissions (OIE) | Not required | Analysis, quantification and integration into the transition plan where relevant |
| Transition plan | Required at Step 3 only | Required from Step 2 with a medium-term target; net zero 2050 target required at Step 3 |
| Value chains | Company-level analysis | Analysis by main activity, with upstream and downstream decarbonisation strategies |
| Climate alignment | Internally defined targets | Net zero target by 2050 for scopes 1, 2 and 3, or SBTi validation |
| Energy reporting | Separate from legal obligations | Automatically satisfies Belgian and European legal energy reporting requirements |
Transition timeline
The transition is gradual. Here are the key milestones.
January 2025
SKAO publishes Handbook 4.0. BENOR vzw adapts it to the Belgian context. The official transition period opens.
July 2025
All 3 steps of Handbook 4.0 are certifiable. New candidates can start directly under Handbook 4.0. Already-certified organisations can migrate.
14 January 2027
All certifications must be under Handbook 4.0. Certifications under the previous handbook are no longer valid after this date.
Important: Steps 2 and 3 of Handbook 4.0 require an initial audit, even for organisations already certified under the previous handbook. It is recommended not to wait until 2027 to start the process. Tapio supports you from now to structure your data and prepare for the audit.
Take the next step
In 30 minutes, our experts assess your situation, identify your target step, and show you how Tapio gets you to certification without the administrative complexity.
