Preparing for Swiss CO₂ emission disclosure requirements

With the Swiss CO₂ Act and its associated CO2 Ordinance taking effect on January 1, 2027, there is roughly one quarter of 2026 left to prepare for these mandatory flight emissions disclosures. Here’s what the regulation requires and steps to take before year-end.

What is the Swiss CO₂ Act flight emissions disclosure requirement?

The CO₂ Act and the associated CO2 Ordinance stipulate that beginning January 1, 2027, providers of flight services (including airlines, travel agencies, and online travel platforms) must show the estimated emissions impact of flights departing from or arriving in Switzerland within any customer-facing touchpoint where applicable flight offers are displayed.

Why does the Swiss CO₂ Act require these flight emissions disclosures?

The CO₂ Act is designed to make the climate impact of flying visible at the moment of purchase, helping passengers understand the emissions associated with a given flight and make informed decisions before they book.

What emissions information must be shown?

Providers of flight offers must show estimated emissions as a clear, visible figure in CO₂e (either in kilograms or tonnes) wherever a customer is presented with a flight offer, including:

• Websites
• Mobile apps
• Booking flows
• Online travel platforms
• Internet Booking Engine (IBE)
• Other customer-facing interfaces where a specific flight offer is presented

See Federal Office for the Environment (FOEN)’s guide to emission information in flight offers.

What calculation methodology can be used?

The Swiss regulation does not prescribe a specific calculation methodology. However, the chosen methodology should align with current scientific findings and be available to FOEN upon request.

How can Chooose support with preparation for Swiss CO₂ Act requirements?

Calculation approaches

Chooose can implement multiple different calculation methodologies, and can draw from multiple different data sources depending on a partner’s preferences.

As one option, Chooose can leverage IATA CO2 Connect, pulling from IATA’s compiled operational data from participating airlines and generating emission calculations based on IATA Recommended Practice 1726.

Customer-facing solutions

Chooose’s customer-facing solutions integrate directly into existing systems, including booking flows, web applications, and other digital interfaces — bridging the gap between backend calculations and the front-end experience.

Why is Swiss CO₂ Act compliance more complex than it looks?

Displaying flight emissions across customer-facing channels requires several operational and technical decisions, including:

• Selecting an appropriate calculation methodology and data source
• Identifying every customer-facing touchpoint where flight offers are displayed
• Designing and displaying emission estimates so figures are clear and visible within the customer-facing touchpoints
• Documenting the calculation methodology, data sources, and assumptions for internal review and external disclosure
• Maintaining processes to ensure calculations, their presentation, and supporting documentation are consistent, maintained, and displayed with minimal manual effort, where possible