The aviation and maritime industries continue to advance toward decarbonisation, and sustainability reporting compliance requirements are becoming increasingly complex. Airlines, maritime operators, and fuel suppliers navigate various and overlapping regulatory frameworks, such as the Renewable Energy Directive III (EU RED III), the ReFuelEU Aviation and FuelEU Maritime regulation, as well as the EU & UK Emissions Trading System (EU/UK ETS).
These mandatory frameworks require robust evidence across the entire supply chain to ensure that the fuels used meet stringent sustainability and greenhouse gas (GHG) savings criteria. Traditionally, this evidence has been provided through a Proof of Sustainability (PoS) document.
Proof of Sustainability (PoS) and the Challenge of Single-Use Documentation
But once the PoS document is surrendered to the authorities, it cannot be reused – creating a documentation gap for downstream operators in the supply chain, such as airlines, which rely on verifiable data for ETS reporting. While the rule prevents double-counting of already certified fuel volumes, it often leaves airlines or maritime operators without the documentation needed to substantiate proper emission-reduction claims. This is where the ISCC Proof of Compliance (PoC) framework comes into play – a practical and reliable solution to close the documentation gap.
Proof of Compliance (PoC) as the Solution to the Problem
The PoC framework enables downstream transfer of verified sustainability and GHG information when the original PoS is no longer available. It complements existing ISCC EU certification without replacing the PoS, thereby ensuring transparency and credibility throughout the supply chain.
What’s inside a PoC?
PoC’s are intentionally designed to closely mirror the layout and structure of a PoS, ensuring continuity for downstream users such as airlines and shipping companies, who are already familiar with PoS documentation. Like a PoS, the PoC contains details on product types, certified quantities, and a confirmation of compliance with ISCC EU sustainability and GHG emissions savings criteria. Therefore, each PoC comes with:
- Identification and traceability support: Each PoC includes a unique document ID, date of issuance, and a clear reference to the original PoS (including the PoS ID). It also confirms when the PoS was surrendered or marked for submission. By doing so, the Proof of Compliance framework avoids introducing an entirely new format, while upholding full transparency and traceability.
- A regulatory context: A PoC also specifies the compliance or incentive scheme under which the original PoS was used (e.g., EU RED III, UK RTFO) and the regulatory purpose for which the PoC is intended (e.g., UK & EU ETS emissions reporting), creating a transparent basis for regulators and downstream reporting.
When can a PoC be issued?
While a PoC cannot replace the original PoS, it serves as a supporting document for downstream compliance, building on the PoS already employed upstream. The original PoS document must have been either surrendered or marked for submission to the authorities and should not be used for any other purpose. Additionally, claims for a fuel batch must be admissible under the relevant legislation.
Proof of Compliance in the Aviation Sector
In 2025, Air bp became the first organisation to integrate the ISCC PoC Trader Scope into its ISCC EU certification. Discover shared insights from ISCC and Air bp on this milestone for compliance and sustainability.
PoC in Practice: Transparent Decarbonisation Through Reliable Documentation with ISCC
With growing recognition by authorities and adoption by maritime and aviation operators, the Proof of Compliance framework provides an easy way to document transparent decarbonisation measures.
At the same time, the PoC reflects our commitment to addressing pressing market challenges facing ISCC System Users. In this case, by offering a standardised, reliable approach to compliance documentation, enabling stakeholders to navigate the vast and complex regulatory landscape with confidence.
Facing Documentation Gaps in Your Supply Chain?
Then take a closer look at our latest “ISCC Proof of Compliance Guidance Document (v1.1)” and explore how PoC supports sustainability reporting for the aviation and maritime sector in more detail.