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 Pennsylvania (PA), 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 PA, a written lease provides clearer evidence of the terms agreed upon and is generally considered more protective, especially for tenants. It is essential for tenants to read and understand the lease before signing. Any modifications to the lease should be negotiated with the landlord, and if agreed upon, should be written into the lease and initialed by both parties to ensure the changes are legally binding. This could include changes such as pet policies and associated deposits. It's important to note that Pennsylvania's landlord-tenant laws, which can be found in the state's statutes, supplement the lease agreement by providing additional rights and responsibilities that may not be explicitly covered in the lease. These laws are designed to provide a legal framework for the landlord-tenant relationship and must be adhered to regardless of the lease provisions.