An Airbnb lease addendum contains language that is attached to a lease agreement and states whether or not the tenant is able to rent the property on the website Airbnb. If allowed, the tenant would be able to sublet the property and rent on a short-term basis in accordance with local laws. Depending on the arrangement between the landlord and tenant, most commonly the tenant would be allowed to keep all profits from renting on Airbnb as long as the monthly rent is paid.