What happens if a guest decides not to stay after checking in?

[Grant0]

My guests checked in yesterday. Today they informed me they are not planning on staying with me for the rest of their stay since they feel the walk from the subway is unsafe (it's not). Am I obligated to refund them? How does it work in this case?

[Keith1]

Your guest cancellation policy will apply.  

they're detailed here: https://www.airbnb.com/home/cancellation_policies

This assumes the guest actually cancels which is in their best interest to do.

You'll want to avoid them making a claim later asking for a refund after you've had no opportunity to rebook the unused nights.

[Grant0]

Aha, thanks! I was not able to find that page myself!