Trusting the Data (part 1) – The Role of Limited Assurance in Aircraft Leasing

More than six months have passed since the EU’s Omnibus announcement, which redefined the scope of sustainability reporting under CSRD and removed aircraft lessors from mandatory disclosure requirements. Yet across the aviation finance value chain, in Europe and globally, the momentum behind carbon emissions reporting continues to build. Increasingly, stakeholders are not just asking for numbers, but for numbers they can trust. For aircraft lessors, Scope 3 emissions generated by leased aircraft represent the most material component of their climate impact. So even in the absence of regulatory obligations, the question remains: is the data credible, and can it stand up to scrutiny?

Limited v Reasonable Assurance

The emergence of limited assurance in sustainability reporting marks a shift in how ESG data is evaluated. Unlike reasonable assurance, the standard applied to financial statements, limited assurance involves a lighter touch, focusing on plausibility and consistency rather than exhaustive verification. However, the rollout of CSRD has exposed challenges in applying limited assurance. During Wave 1 reporting in 2024, companies and auditors operated without a formal audit standard. The International Auditing and Assurance Standards Board (IAASB) only released a draft of ISSA 5000, the proposed global standard for sustainability assurance, in late 2024, with an effective date of 15 December 2026.

This gap led to:

• Subjectivity in how assurance providers interpreted what constituted sufficient evidence
• Inconsistency in audit procedures across firms and jurisdictions
• Lack of coherence and agreement on the scope and depth of work required to issue a limited assurance opinion

Based on the experience and learnings from Wave 1 reporters, and as the limited assurance standard and audit processes continue to evolve, platforms supporting sustainability reporting must be built for transparency and resilience. The ability to trace data sources, explain methodologies, and reproduce results is no longer a nice-to-have but rather a baseline expectation. These are precisely the qualities that platforms like PACE are designed to deliver.

Why volunteer to meet assurance?

While aircraft lessors are no longer in scope for mandatory sustainability reporting under CSRD, the relevance of emissions data, particularly Scope 3, remains. For some, voluntary assurance offers a way to demonstrate leadership, investor readiness, or alignment with internal ESG goals. But for many others, assurance may never be part of their strategy, and that is entirely valid. What matters more broadly is the integrity of the data itself. In a sector where Scope 3 emissions are material but complex, having confidence in the underlying data is increasingly important. Whether used for internal reporting, stakeholder engagement, or strategic planning, robust emissions data helps lessors stay ahead of expectations, even in the absence of formal assurance.

How PACE Supports the Limited Assurance Process

As emissions accountability shifts from compliance to strategic relevance, the ability to quantify and explain Scope 3 emissions credibly is becoming a differentiator. PACE’s platform has been designed with this in mind, enabling lessors to meet growing demands for climate disclosure with confidence. PACE provides:

• Aircraft-level Scope 3 emissions data tailored to each portfolio
• Detailed outputs including emission factors, activity data, and calculation logic
• Reproducible datasets that support audit-readiness and internal validation

So whether used for assurance, investor reporting, or internal ESG strategy, PACE’s system-based approach ensures emissions data is consistent, transparent, and defensible. Even for those lessors not pursuing assurance, knowing that PACE data has passed independent scrutiny offers reassurance of its quality and reliability.

Author:

	Denise Pigott is Sustainability Lead for Fexco Group and holds an MSc in Management for Sustainable Development. Denise holds qualifications in environmental law and climate change, and prior to her current role spent over two decades in Fexco’s finance and governance teams leading statutory and group reporting for the group.