The most important source of information about the rights and responsibilities of residential landlords and tenants is the written lease agreement. Some landlords prefer oral agreements, but it is more common for them to require the tenant's signature on a written lease—and a written lease protects the tenant more than an oral agreement. Be sure to read the lease carefully before you sign it.

If a tenant wants to change part of the lease, the tenant should discuss it with the landlord. If the landlord agrees, the landlord and tenant should decide how they want to word the change and then write it into the agreement. Both the tenant and the landlord should then initial the change. For example, many standard leases prohibit pets, but the landlord may be willing to accept a pet if the tenant puts down extra money as security (a pet deposit) to protect against any damage the pet might do.

A state’s landlord-tenant laws may provide additional rights and responsibilities and further define the rights and responsibilities identified in the lease agreement. These laws vary from state to state and are usually located in a state’s statutes.

In Iowa, the written lease agreement is indeed a crucial document for both residential landlords and tenants as it outlines their rights and responsibilities. While oral agreements are legally binding in Iowa, a written lease provides clearer protection and is generally preferred. Tenants should thoroughly review the lease before signing and negotiate any desired changes with the landlord. Any amendments should be written into the lease and initialed by both parties to be legally effective. For instance, if a tenant wishes to keep a pet despite a no-pet clause, they can negotiate a pet deposit as an amendment to the lease. It's important to note that Iowa's landlord-tenant laws, which can be found in the Iowa Code, supplement the lease agreement by providing additional rights and responsibilities that may not be explicitly mentioned in the lease. These laws are designed to ensure fair practices and cannot be overridden by the lease agreement. Therefore, tenants and landlords should be aware of these statutory provisions as they form part of the legal framework governing residential tenancies in Iowa.