CORSIA Explained for Airline Management: A One-Page Brief

What CORSIA asks of an airline, which teams own each part, and how the cost of offsetting is built up, written for a management meeting rather than a specialist.

This page is for the people who sign off budgets and policies at an airline: the CFO, the head of operations, the accountable manager. It is not a technical manual. It tells you what the obligation is, who in your organisation should own each piece, and how the bill is put together, so you can ask your team the right questions.

The obligation in three sentences

CORSIA is the carbon scheme for international aviation, adopted by ICAO (the UN body for civil aviation) in 2016. Airlines above a size threshold must measure the CO₂ from their international flights every year and report it to their national authority. On routes between participating States, they must also buy and cancel carbon units to cover their share of emissions growth above a fixed baseline.

That is the whole idea. Everything else is detail about how to measure, how to report, and which units count.

Two separate duties

It helps to think of CORSIA as two jobs that run on different clocks.

Monitoring, reporting and verification (MRV). Every year, the airline records fuel burned on each international flight, turns it into CO₂, has an independent verifier check the numbers, and files the report. This applies once you cross the threshold (more than 10,000 tonnes of CO₂ a year from international flights, using aeroplanes over 5,700 kg maximum take-off mass). You can test your own position with our coverage self-check.

Offsetting. Over each compliance period, the airline cancels eligible emissions units equal to its calculated offsetting requirement. Not every route triggers this; it depends on whether both States on the route are participating.

MRV is a data and process job. Offsetting is a procurement and finance job. Treat them that way internally.

Who should own what

Task	Usual owner	What management should ask
Emissions monitoring plan	Flight operations or fuel efficiency team	Is the plan approved, and does it match how we actually record fuel?
Annual emissions report	Environment or compliance lead	Has the verifier signed off, and were there any findings?
Offsetting estimate	Finance with compliance	What volume do we expect to owe, and on what assumptions?
Buying units	Procurement or treasury	Are the units eligible for the right period, and is the paperwork complete?
Registry account and cancellation	Compliance	Do we hold an account, and who can operate it?

In smaller operators one person often does all five. That is fine, provided someone senior reviews the offsetting estimate and the purchase, because those carry the money.

How the cost is built up

You will not find a price on this page, and you should be wary of anyone who quotes one without knowing your fleet. What we can show is the structure.

Your emissions. Fuel burned on in-scope international flights, multiplied by a fixed factor (3.16 tonnes of CO₂ per tonne of Jet-A or Jet-A1).
The growth share. CORSIA only asks the sector to offset growth above its baseline. From 2024, that baseline is 85% of 2019 emissions. ICAO publishes a growth factor each year, and your emissions are multiplied by it to give your raw requirement.
Deductions. If you use eligible lower-carbon fuels, the claimed reduction comes off.
The unit price. The remaining tonnes are multiplied by what you pay per eligible unit, which depends on supply, vintage and whether the host country has authorised the units.

Our offsetting calculator walks through steps one to three. You enter the growth factor yourself from the official figure, so the result stays tied to the published number rather than to our guess.

What tends to go wrong

From what we see with operators, the costly mistakes are rarely in the arithmetic. They are in timing and paperwork:

Buying late. Eligible supply for a given period can be thin, and a rushed purchase leaves little room to check documents.
Buying the wrong units. A credit that is fine for a voluntary claim may not meet CORSIA rules for vintage or authorisation. Our eligible units checklist covers the tests.
No registry access. Opening an account takes time, and you cannot cancel units without one, unless a partner cancels on your behalf with proper records.
Weak data trail. Verifiers want to trace each figure back to fuel records. Gaps found late are expensive to fix.

Decisions for the management team

If you take one thing from this brief into a meeting, make it this short list:

Confirm whether we are in scope for reporting, offsetting, or both.
Name one owner for MRV and one for offsetting, with a senior reviewer.
Agree how far ahead we buy units and how much budget we hold for them.
Decide whether we want our own registry account or a partner to manage cancellation.

For the yearly sequence of these tasks, see the compliance calendar. Official texts are on ICAO's CORSIA pages, and Indian operators report to the DGCA.

When you are ready to turn this into a plan, our CORSIA services cover each step from the monitoring plan through to cancellation, and we are glad to start with a short call.