A lease addendum is a separate signed document that adds terms to a lease: a smoking policy, parking rules, a satellite dish policy, utility responsibilities, or anything else the original lease left out. Once both parties sign, the addendum is part of the lease and enforceable like any other clause.
Use an addendum when you are adding new terms; use a lease amendment when you are changing terms the lease already contains.
The most common lease addenda
- Smoking and vaping policy
- Parking and vehicle rules
- Appliance responsibilities and included equipment
- Utilities and shared meter arrangements
- Pool, hot tub, or trampoline rules
- Home business or short-term subletting restrictions
Pets are the classic case and have their own dedicated form: the pet addendum covers deposits, pet rent, and animal-specific rules.
Addendum vs amendment
An addendum adds terms on a subject the lease did not address; an amendment rewrites terms the lease already contains. The distinction matters for clarity, not validity: both need signatures from landlord and tenant, and both become part of the lease. If you are raising rent or changing an occupancy clause, use an amendment; if you are introducing a parking policy that the lease never mentioned, use an addendum.
Mid-term addenda need tenant consent
A landlord cannot impose new terms during a fixed lease term by simply mailing an addendum. Until the tenant signs, the added terms do not bind them. At renewal time, new addenda can be made a condition of the new lease.
Writing an addendum that holds up
Identify the lease precisely by parties, property, and signing date. Number each added term and write it as a complete rule: what is allowed or prohibited, any fees or deposits attached, and what happens on violation. State that the addendum is incorporated into the lease and that the lease otherwise stays unchanged. Finally, have every person who signed the lease sign the addendum, and staple a copy to each copy of the lease.
Frequently asked questions
Does a lease addendum need to be signed by both parties?
Yes. An addendum only binds the parties who sign it. A policy the landlord posts or mails without signatures is not part of the lease, and a tenant cannot add terms unilaterally either.
Can an addendum be added after the lease is signed?
Yes, at any time, as long as both parties agree and sign. During a fixed term the tenant is free to decline; at renewal the landlord can make signing the addendum a condition of renewing.
How many addenda can a lease have?
There is no limit. Give each one a clear title and date, and keep them attached to the lease so the full set of terms stays in one place.
Does a lease addendum need to be notarized?
No. Like the lease itself, the signatures of landlord and tenant make it binding in every state.
What if the addendum contradicts the lease?
A well-drafted addendum states that it controls over the lease as to its subject matter, which is what this template does. If you are deliberately changing an existing clause, a lease amendment is the clearer instrument.