ISCC EU: What changes in audits 2025
If you are a certified operator or preparing for certification, 2025 marks a turning point: the regulatory package of RED III and the delegated acts on hydrogen and RFNBOs redefined criteria, metrics and verification scopes — and ISCC has already incorporated concrete changes to the audit checklist. Between them, a novelty that affects many biofuel routes: the requirement of hydrogen with “non-zero” GHG value when used as a process input. In this practical guide, I explain what changes in audits, how to demonstrate compliance and where the greatest risks lie — with a focus on those experiencing the ISCC I Post-Red III not day by day.
1) The background: RED III, targets and acts for hydrogen/RFNBO
A RED III (Directive (EU) 2023/2413) raised the binding renewable target to 2030 for at least 42,5%, with ambition to 45%, in addition to new sectoral goals (transport, industry, heating and cooling). No transport, Member States can follow GHG intensity targets or minimum share of renewables, and the industry gained specific targets for the use of RFNBO (renewable hydrogen and derivatives).
Two “sister” delegated acts detail the what is renewable hydrogen (RFNBO) e how to prove its Renewability: electricity additionality rules, temporal and geographic correlation, and a methodology to account for GHG emissions throughout the life cycle. These instruments are now the compliance benchmark used by schemes such as ISCC in audits.
2) The H rule₂ “non-zero”: what exactly changes
In 22 september 2025, the ISCC made explicit: hydrogen used as an input in biofuel production processes cannot be classified as waste with zero emissions. Audited as “zero”, becomes major NC (serious non-compliance) with potential to suspension or withdrawal of certificate. In other words, where there is H₂ on the route (hydrogenation, hydrotreatment, desulfurization, etc.), it is mandatory to assign a traceable emission value — either through primary data from the supplier, either by recognized factors/methodologies.
This turn responds to the spirit of RED III and the new GHG methodology for hydrogen (including the recent methodology for low carbon hydrogen, with a threshold of 70% reduction vs. reference fossil), reinforcing that “zero por default” to H₂ is not acceptable.
Practical implications
- Mass balance and data trail: H₂ becomes an input with its own footprint. You will need show origin, labeling (RFNBO/low carbon/other) and emission factor in the calculation form (ISCC 205/205-1).
- Baseline change: routes that gained “relief” with supposedly “zero” H₂ may see increase in Ep/Ep-equivalent (or relevant processing block), affecting the Co.₂e/MJ end and the margins in front of the thresholds.
- More incisive audit: O control point enters audit planning as a mandatory item for 2025/26. Certifiers must verify the presence of H₂, the classification applied and the GEE die used.
3) What will the auditor ask for (and how to prepare)
O ISCC I Post-Red III brings a set of additional checks, especially when there is RFNBO in the chain:
- Evidence of H eligibility₂
- Proof that the electricity used in the electrolyzer complies additionality, temporal correlation e geographical (if applicable), or documentation of the “low carbon” nature according to the 2025.
- PPA Contracts, Guarantees of Origin, time/month records, bidding zone boundaries.
- GHG methodology and applied factor
- ISCC compliant calculation 205/205-1 (spreadsheets, hypotheses, allocation) with H emission factor₂ documented (primary data or secondary factor as permitted).
- Mass balance and traceability
- Integration of H₂ as an input in mass balance: inputs/outputs, losses, inventories and reconciliation by certification period.
- Checks RFNBO (if applicable)
- Use of RFNBO audit procedure: list of best practices, NC points and corrective measures.
4) Affected routes and risk “hot spots”
- Hydrotreatment and hydrogenation (HVO, PURE HEFA, renewable diesel, co-processed): any consumption of H₂ starts to charge actual weight in inventory. Where the H₂ supplier does not deliver reliable data, there is a risk of NC due to lack of evidence.
- Co-processing in refineries: the coherence between share bio (ato 2023/1640) and accounting for H₂ becomes critical in order not to “mask” emissions.
- Importers: long chains with multiple H₂ suppliers require enhanced due diligence to avoid falling into an unfavorable default or insufficient documentation.
5) How to demonstrate compliance (step by step)
- Map the usage of H₂ in your process (amount, pureza, injection points).
- Rate the H₂ (RFNBO; low carbon; other) and collect evidence: PPAs, GOs, temporal correlation records, electrical frontier, or evidence of the threshold of 70% for low carbon.
- Get (or legitimately estimate) the emission factor of H₂: Supplier primary data is preferable; document assumptions if using allowable secondary factor. Never treat like zero.
- Update the GHG calculation ISCC compliant 205/205-1 (master spreadsheet), ensuring allocation e units consistent up to gCO₂e/MJ.
- Adjust the mass balance: record the H₂ in the scope, volumes, losses and reconciliation by audit period.
- Carry out an internal pre-audit using the RFNBO procedure do ISCC to check gaps, Potential NC and corrective measures before the auditor.
6) What changes most in audits 2025
Beyond “non-zero” H₂, ISCC communicated in 2025 a set of operational reinforcements (p. ex., auditor rotation, mandatory upload of lists of covered sites, sourcing contacts, Documentary updates and system webinars). These movements signal greater standardization and transparency — and less tolerance for recurring gaps. It's worth following the section System Updates ISCC for current schedules and versions.
7) Common errors (and how to avoid them)
- Assuming “zero” by analogy: the fact that certain wastes have “zero” not authorizes extending this to H₂; the rule of 22/09/2025 it's clear.
- Incomplete electricity data no RFNBO: additionality and temporal correlation need temporal evidence (hour/month) and geographic.
- Traceability Gaps: H₂ that “comes and goes” without reconciliation in the mass balance raises an alert in audit.
- Outdated spreadsheets (ISCC 205/205-1): old versions may generate inconsistency with RED III; Check out the release and review notes.
8) Quick checklist for your next audit
- Confirm current version of ISCC documents (205, 205-1, 202-6/RFNBO, audit procedures).
- Identify everything use of H₂ and collect evidence of emission factor. Never “zero”.
- Validate RFNBO Eligibility (additionality, temporal, geographical) if applicable.
- Update GHG calculation and Co.₂e/MJ with incorporated H₂.
- Check mass balance and reconciliation of stocks/inflows.
- Carry out internal pre-audit based on the ISCC RFNBO procedure.
Conclusion O ISCC I Post-Red III consolidates the transition from “documentary compliance” to compliance based on traceable data and robust GHG methodologies — especially when there is hydrogen in the route. With the H rule₂ “non-zero” from 22/09/2025, the consistency between evidence of eligibility, emission factors e mass balance will be the divider between fluid audits and long corrective plans (or even suspensions). Those who get ahead — reviewing H₂ contracts, PPAs, time records and spreadsheets 205/205-1 — arrives at the audit with a solid number, coherent narrative and minimized risk.
Find out more about ISCC, RED and European regulations in our blog.