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 Montana, the 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 Montana, a written lease provides clearer protection and is generally preferred. It is essential for tenants to thoroughly read and understand the lease before signing. Any modifications to the lease should be mutually agreed upon by both the landlord and the tenant, and these amendments should be written into the lease and initialed by both parties to ensure they are legally enforceable. For instance, if a landlord agrees to allow a pet contrary to a standard no-pet policy, this should be documented in the lease along with any additional terms, such as a pet deposit. It's important to note that Montana's landlord-tenant laws, which can be found in the Montana Code Annotated (MCA), may supplement the lease agreement by providing additional rights and responsibilities. These laws take precedence over the lease terms and cannot be waived by agreement of the parties. Therefore, both landlords and tenants should be familiar with these statutory provisions in addition to the terms of their lease agreement.