@Tierney7 I think Airbnb is referring to altering the reservation. If that's what they keep on telling you, once the reservation is altered, make sure you have clear documentation of the guests smoking and any other supporting documentation, such as screenshots of your house rules stating the no-smoking policy, that way you will be able to file a damage claim after the guest's check out. Submit it via Airbnb Resolution Center upload the documentation and request the cost to fix the smell of smoke. Also, ask Airbnb support to intervene based on the guest’s violation and your claim. Hope this at least helps!