Key money, also known as a key deposit or a key fee, refers to the amount of money that a tenant pays to a landlord as a security deposit when leasing a property. It serves as a guarantee for the landlord to cover any damages incurred during the tenant's occupancy. Other synonyms for key money may include a security deposit, a rental deposit, a lease deposit, or a move-in fee. These terms essentially refer to the same concept of the tenant providing a sum of money to the landlord at the beginning of the lease agreement. Despite its various names, key money remains a common practice in many renting arrangements.