The cost of running UTMB is about to go up, not because of higher entry fees, but because of how runners get to the race.
Beginning with the 2026 edition of UTMB Mont-Blanc, all participants will be required to pay a mandatory carbon contribution tied to the emissions generated by their travel to and from the Mont-Blanc valleys. The contribution will apply to runners in all races and will be calculated individually based on distance and mode of transport.
UTMB says the measure is necessary to address the largest source of the event’s environmental impact. According to the organization’s own carbon footprint analysis, runner travel accounts for nearly 86 percent of total emissions associated with the event.
How the carbon contribution works
The carbon contribution will be calculated during the registration process using a module built directly into UTMB’s existing platform.
Runners will be asked to provide two pieces of information: their primary residence or departure address, and their main mode of transportation to the event. Based on that information, the system will calculate emissions for a round trip and apply a fixed price of €25 ($29.26) per metric ton of CO₂ equivalent (tCO₂eq).
UTMB acknowledges that different carbon calculators can produce different results. The organization says the tool used for registration was chosen because it could be easily integrated into the system and kept simple for runners. The result shown during registration will be the amount charged.
What runners can expect to pay
The final cost varies widely depending on where runners are coming from and how they travel.
UTMB has published estimated ranges to give runners a sense of what to expect:
- France: roughly €0.50 to €10
- Switzerland, Italy, Spain, United Kingdom: up to €20
- United States and North America: approximately €60 to €115
- Asia: about €80 to €160
- Oceania: at least €150
- South America: around €100 to €150
- Africa: from €25 up to roughly €170 for long-haul travel, such as from Cape Town
The contribution is separate from entry fees and comes on top of other new requirements, including a lottery system that now offers a bonus to runners who commit to lower-carbon travel.
Where the money goes
UTMB says 100 percent of the carbon contributions collected will be transferred to an independent intermediary organization responsible for selecting and auditing climate projects. In 2025, UTMB worked with EcoAct, and says future partners will meet the highest certification standards.
The projects funded are intended to either increase carbon sinks or avoid emissions. UTMB says some projects will have a local impact in the French departments hosting the race, while others will support international initiatives.
In 2025, when the contribution was voluntary, UTMB collected roughly €8,000 ($9,365) from runners. Combined with contributions made by the UTMB Group itself, the total reached approximately €25,000 ($29,266), which was used to support projects in Haute-Savoie and Brazil.
Verification and enforcement
Runners will be required to submit proof of residence between March and June as part of the verification process. UTMB will check that the declared address and mode of transport are consistent with the carbon contribution paid.
Only primary residences are accepted as proof. Letters from friends or hosts are not permitted. Runners staying elsewhere for more than six weeks before the event may use that location as their departure point if it is genuinely where their journey begins.
Any proven fraud will result in cancellation of registration without a refund of entry fees. Running Stones will be returned.
If a runner cancels their entry in line with UTMB’s official cancellation policy, the carbon contribution will be refunded. If the registration is cancelled due to failure to comply with low-carbon travel commitments, the contribution will not be refunded.
Part of a broader shift
UTMB says the carbon contribution is not meant to replace efforts to reduce emissions, but to address what remains unavoidable. Since 2024, the organization has covered emissions related to staff, volunteers, guests, on-site transport, and race operations.
Together with new travel rules that affect lottery odds, the carbon contribution marks a significant shift in how the event approaches sustainability, and how much responsibility it places on individual runners.
For many, the added cost will be modest. For others, especially those traveling long distances, it will be noticeable. Either way, from 2026 onward, the true cost of getting to UTMB will be more explicit than ever before.
