A deposit or bond is required in Lisbon. It can be up to three months' rent, and you'll usually have to pay it all in one go. However, you're allowed to pay in two installments: for example, half at the start of tenancy and half before your first review date (usually after six months). The landlord should give you proof that they've paid the deposit into a special account called 'Deposit Protection'. You should always check this before signing any paperwork—and don't forget to ask a friend or family member for their opinion too.