State laws generally require a written lease agreement between a landlord and tenant. The agreement controls the tenancy, and covers issues such as rental payments, security deposits, and the duty to repair or maintain the premises. Lease agreements are temporary; most residential agreements last at least one year. Once an agreement is signed, it remains in effect as-is, unless one party follows proper procedure to modify it.
When either party to a lease agreement wants to change the original terms of the contract, they generally have two options: create a new agreement or create an addendum that simply adds to the existing contract. Common situations calling for a lease addendum include prohibiting smoking when the lease agreement was silent and no other law prevented the tenant from smoking within the premises, or adding clauses governing pets. Both parties -- landlord and tenant -- must give proper notice to the other party before changing the lease terms.
The terms of a written lease, once signed, are binding. A party cannot unilaterally change the terms without proper notice. If a landlord wants to enforce a lease addendum, the landlord must provide the tenant with proper notice of the intended changes and the tenant must agree to the changes and sign the addendum agreement. The type of required notice depends on state laws and may be dependent on the facts. In California, for example, most lease addendums and changes require at least 30-days notice, and can never be less than 7-days notice.
Even if the landlord proposes an addendum and complies with the relevant notice procedures, the tenant does not have to sign it. The terms of the original agreement remain in effect and the landlord cannot enforce the proposed terms. When the lease agreement ends, the landlord could add the provisions to a new agreement and require the tenant to sign the new agreement or find a new rental unit.
A tenant cannot be evicted for refusing to sign a lease addendum. If you believe that your landlord is strong-arming you into signing a new agreement that adds something you do not agree with, you should seek legal representation. Landlord-tenant agreements are contractual documents that affect the legal rights of the parties involved. Before you sign a lease agreement or an addendum, carefully read through the document and seek clarification about terms used or the effect of a certain clause as necessary.