What Aviation Fuel Producers Need to Know About ISCC EU and ICAO Compliance

CORSIA is no longer on the horizon. It’s here, and it’s reshaping how Sustainable Aviation Fuel (SAF) is tracked, certified, and credited globally.

If you are producing SAF and want it to qualify for airline claims or regulatory incentives, ISCC EU alone may not be enough.

Here’s what you need to know, with no fluff.

1. What Is CORSIA and Who Enforces It

CORSIA stands for the Carbon Offsetting and Reduction Scheme for International Aviation. It was developed by ICAO (International Civil Aviation Organization), a specialized UN agency.

Its goal is to cap net CO₂ emissions from international flights at 2019 levels. Airlines can meet their targets through offsets or, preferably, by purchasing CORSIA-eligible SAF that meets strict lifecycle and traceability rules.

CORSIA is coordinated by ICAO but enforced through national aviation authorities that collect, verify, and report emissions data from airlines and fuel producers.

2. What Counts as CORSIA-Compliant SAF

To be eligible under CORSIA:

• The feedstock must appear on ICAO’s approved list (for example, used cooking oil, tallow, certain agricultural residues).
• The production pathway must meet ICAO’s lifecycle GHG thresholds.
• The entire supply chain must be traceable under an ICAO-approved sustainability certification scheme such as ISCC.
• Each batch must be accompanied by a CORSIA Certificate of Sustainability (CoS) containing ICAO-specific emission factors and sustainability data.

Without these elements, SAF cannot be claimed by airlines for CORSIA credit, even if it meets RED III sustainability criteria.

3. Does ISCC EU Cover CORSIA

Yes, but only if you’re certified under the ISCC CORSIA scope.

ISCC is one of ICAO’s Approved Sustainability Certification Schemes (ASCS). To qualify, your site must undergo an ISCC CORSIA audit, which can be combined with ISCC EU but follows its own checklist covering:

• Feedstock eligibility under ICAO rules
• GHG calculation using the ICAO methodology, not RED III
• Mass balance and traceability alignment specific to aviation fuels
• CORSIA-specific documentation and record keeping

If you are already ISCC EU-certified, you’re halfway there but not automatically compliant with CORSIA until you are audited under the ISCC CORSIA framework.

4. What Documentation Is Required

You will need:

• CORSIA-aligned Supplier Declarations for all inputs
• Batch-level mass balance logs kept separate from RED III records if needed
• GHG calculation spreadsheets using the ICAO lifecycle method
• CORSIA Certificates of Sustainability (CoS) with ICAO-required data fields
• Audit records linking SAF batches to approved routes and airline buyers

Most SAF producers now manage dual compliance tracks: one for RED III and one for CORSIA, with separate calculations, declarations, and audit packages.

5. What Goes Wrong in CORSIA Audits

Here’s what ISCC auditors commonly flag:

✅ Feedstock listed under RED Annex IX but missing from ICAO’s approved list
✅ GHG savings calculated using RED methodology (not accepted by ICAO)
✅ Batch IDs not unique across markets, creating conflicts in registry submissions
✅ Supplier documents missing mandatory ICAO fields
✅ Mass balance entries combining SAF and non-SAF volumes

Another recurring issue is the missing link between CORSIA batches and airline end-use routes, which auditors now check closely.

Fixing these manually is tedious, especially when data is scattered across spreadsheets, PDFs, and multiple systems.

6. How Carboledger Helps With CORSIA

We’ve designed Carboledger’s system with dual-path compliance in mind for SAF producers operating across RED III, CORSIA, and voluntary carbon schemes.

✅ Smart Balance

Maintain parallel ledgers for RED III and CORSIA, each with its own inputs, outputs, CoS records, and audit logs.

✅ Carbon Data Exchange

Generate ICAO-aligned LCA templates and reconcile GHG values with certified SAF batches and flight routes.

✅ AI Compliance Agents

Auto-check feedstock eligibility, match supplier documentation to ICAO templates, and flag non-conformities before the audit.

✅ One-Click Document Exports

Download complete CORSIA audit packets: Supplier Declarations, GHG files, traceability maps, and Certificates of Sustainability with all ICAO-required data fields.

Final Takeaway

CORSIA isn’t just a new label. It’s a new compliance logic.

Fuel that qualifies under RED III may not automatically count for aviation use. CORSIA introduces its own sustainability criteria, lifecycle model, and documentation pathway that operate alongside, not within, RED III.

The good news: if you are already ISCC-certified, you have the foundation.
The challenge is dual tracking, data segregation, and documentation precision, and that’s exactly what Carboledger helps you master.

Reach out to explore CORSIA support, dual-path ledgers, and integrated GHG calculators built for ICAO compliance.