Lease and Pet Documents: Addenda and Agreed Changes

Lease and pet documents are agreements, not notices. A notice is something one party sends to the other. An addendum changes the lease, and a lease can only be changed by the people who signed it. That difference shapes everything about how these documents are drafted, signed and kept.

What these documents do

An addendum adds terms to an existing lease without replacing it. The most common one in residential renting is the pet addendum: it identifies the animal, states who is responsible for its care, damage and nuisance, omits payment clauses for separate review, and sets out the conditions under which the permission can be withdrawn. Once both parties sign, the addendum is read together with the lease.

Other agreed changes, such as an early end to a fixed-term lease, start with a request. The early lease termination letter is that request from the tenant’s side. The signed agreement that follows should be drafted on its own and signed by everyone on the lease.

Who prepares and signs them

Either party can prepare an addendum, but it only takes effect when every party to the lease signs it. In practice the landlord or manager usually drafts it and the tenant reviews it. Date the signatures and give every signer a complete copy. An addendum signed by one tenant does not bind a co-tenant who did not sign.

Pets versus assistance animals

A pet addendum is for pets. An assistance animal (a service animal or a support animal that a person with a disability needs) is treated differently under federal fair housing law, and pet fees, pet deposits and pet rent are generally not applied to it. If a tenant tells you the animal is an assistance animal, do not route the conversation through the pet addendum. Read the accommodation requests page, which explains that our request tool is paused while withdrawn federal guidance is reviewed, and consider qualified advice before you respond. The pet addendum generator never applies its terms to an assistance animal automatically.

Typical mistakes

1. Charging a fee the law does not allow. Some states cap pet deposits as part of the total security deposit, some treat non-refundable fees differently, and some cities add rules of their own. This version of the generator leaves every pet fee, pet deposit and pet rent line out, and tells both parties to agree on them separately in writing after checking state and city rules.
2. Vague animal descriptions. “One dog” is not enough when a dispute arises. Record the species, breed if known, name, approximate weight, color and any license or vaccination information the tenant chooses to provide.
3. Treating the addendum as a notice. Posting a pet addendum on a tenant’s door does not make it part of the lease. It needs assent, which means signatures.
4. Forgetting the lease. The addendum should name the lease it amends (parties, property and start date) and say that all other lease terms stay the same.
5. Not keeping a signed copy. Each party should keep a full, signed copy with the lease. Scans are fine as long as everyone has the same version.

What to check

• The lease: any existing pet clause, the deposit clause and the amendment clause.
• Your state’s security deposit rules, since a pet deposit is often counted inside the overall deposit limit.
• Local ordinances on animals, breed rules and the number of animals per unit.
• Insurance requirements, which sometimes affect what a landlord can agree to.
• Whether the animal is an assistance animal, which takes the matter out of this category.

If you are unsure where to start, which rental letter do I need walks through the common situations. For delivery and record-keeping, see how to deliver a letter and keep a copy.

LetterForgeUSA provides document drafting tools and general information, not legal advice. Rules depend on your location and circumstances.