The trek is a sponsored challenge event organised by Childreach itself (more about challenge events on their website here). I'm trekking as part of a larger university group undertaking the challenge, which last year was able to raise almost £300,000 toward the charity, all told.

Some of the fundraising total will be spent on travel expenses, but the majority of it will go directly to the charity, just as with a sponsored mountain climb, skydive, or marathon. Ideally, it would be great if all the fundraised money could go towards the charity, but challenges like this give incentive for people to actively take part in fundraising. The fundraising goal is larger accordingly to ensure the majority of money raised does go towards the charity.

Hope that clears up your confusion! Apologies for the lack of clarity.