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 Washington State, the Residential Landlord-Tenant Act (RCW 59.18) is the primary statute governing the rights and responsibilities of landlords and tenants. While oral lease agreements are legally binding in Washington, written lease agreements are indeed more common and provide clearer documentation of the terms agreed upon by both parties. A written lease serves as the most important source of information about the rights and responsibilities of both the landlord and the tenant. Tenants should read and understand the lease before signing, as it becomes a legally binding contract once signed. If a tenant wishes to negotiate changes to the lease, such as allowing pets when the lease prohibits them, these changes should be discussed with the landlord. If agreed upon, the changes should be written into the lease and initialed by both parties to ensure that the modifications are legally enforceable. It's important to note that while the lease agreement outlines specific terms, state law may provide additional protections and obligations that are not negotiable and must be adhered to by both landlords and tenants.