Any property rented our for the purpose of short term rental tenants requires the correct license. Indeed any property rented our long term also needs to follow locals laws, but short term AIRBNB style renting has been restricted and you will need to check area by area. If investing in Lisbon the capital city then buying through a company such as our will give a selection of properties and developments that already have suitable licenses in place in order for you to receive your rental income. Mixed buildings of locals, young people, foreign people, some paying rent, some owners can be impossible for short term rent now, as the condominium of owners (freeholders) all need to agree on almost everything that goes on in that block, and this is rarely easy. If your focus is rental income then buying in a purpose built block is best.