The first phase of CORSIA is entering its final months. For most operators, the 2025 reporting cycle—verified by independent bodies before April 30, 2026, represented the most rigorous data exercise since the program’s inception. However, a verified report is merely the “input” for a larger financial equation.
As we progress through 2026, the industry is operating in a dual-track reality:
While operators have submitted their verified emissions data for 2025, their individual offsetting liability is currently “frozen” in a state of calculation. This liability is determined by the Sectoral Growth Factor (SGF), a variable that reflects the total international aviation sector’s emissions growth relative to the baseline (85% of 2019 levels).
The ICAO Council is mandated to publish the final 2025 SGF by October 31, 2026. This Publication marks the beginning of the 2025 CORSIA offsetting reconciliation process.
For operations and compliance managers, this notification represents the shift from “data management” to “liability management”. Operators must ensure their finance team is briefed on the potential variance in credit prices once these official “offsetting obligations” are issued across the industry simultaneously.
With the 2025 liability quantified by year-end, the focus shifts to the procurement of CORSIA Eligible Emissions Units (EEUs). Unlike the voluntary carbon market, CORSIA has strict eligibility criteria that have evolved for the 2024-2026 period.
A critical development in 2026 is the scarcity of units that carry a Letter of Authorisation (LoA) from host countries.
Under Article 6 of the Paris Agreement, these “Corresponding Adjustments” (CAs) are required to ensure that a carbon reduction is not double-counted by both the aeroplane operator and the country where the project is located.
While the 2025 SGF is issued in 2026, the physical “cancellation” of these credits (marking them as retired in a registry) for the entire 2024-2026 period must be completed by January 31, 2028.
The monitoring conducted right now will undergo independent third-party verification before April 30,2027.
As a Verification Body, we emphasise the following for the 2026 cycle:
On January 1, 2027, while the 2026 verification is still underway, the industry enters the Second Phase.
The 2026 monitoring year is not merely an administrative repetition of 2025. It represents the definitive “close-out” period for the first phase of CORSIA for aeroplane operators. By the end of October 2026, the SGF will provide the final clarity required for determining 2025 offsetting requirements. At the same time, the rigour applied to ongoing 2026 monitoring activities will directly influence the efficiency and outcome of the final Phase 1 verification process in 2027.
Aeroplane operators that maintain a “Verification-Ready” approach throughout 2026, including robust monitoring, data integrity checks, internal controls, and timely record management, will be better positioned to meet both CORSIA offsetting and reporting obligations as the scheme transitions into its Second Phase.
