Lease addendum template: free in Word, or sign it online
Reviewed in October 2026
A lease addendum is a short document that adds or changes terms in an existing lease. Common addenda cover pets, parking, a new roommate, utilities or early termination. It becomes part of the lease once the landlord and every tenant sign it.
Ten documents free, no card. Signed by the landlord and every tenant.
Example filled in with sample data
The full lease addendum
ADDENDUM TO LEASE AGREEMENT
This Addendum is made on [date] between [landlord name] (the "Landlord") and [tenant names] (the "Tenant"), and forms part of the lease dated [date of lease] for the property at [address] (the "Lease").
1. Purpose
The parties add the following terms to the Lease, effective [effective date].
2. Added Terms
[Choose and complete the ones that apply.] (a) Pet: The Tenant may keep [number] [type, breed, name, weight]. The Tenant will pay a pet deposit of USD [amount] and monthly pet rent of USD [amount], and is responsible for any damage, noise and waste caused by the pet. (b) Parking: The Tenant is assigned space [number] for USD [amount] per month. (c) New occupant: [Name] joins the Lease as a tenant and accepts all its terms. (d) Utilities: [Change in who pays each utility]. (e) Other: [describe].
3. Conflict
If this Addendum conflicts with the Lease, this Addendum controls for the matters it covers.
4. 3A. Pet Rules (if 2(a) applies)
The pet will be leashed in common areas, waste will be picked up at once, and the pet will not be left alone in a way that disturbs neighbors. The Landlord may revoke consent after written notice if the pet causes repeated complaints or damage.
5. Rest of the Lease
All other terms of the Lease remain in full force.
6. Signatures
This Addendum may be signed in counterparts and electronically.
Landlord
Name: [name]
Signature: ______________
Date: [date]
Tenant
Name: [name]
Signature: ______________
Date: [date]
What the template includes
Landlord, tenants and the original lease
Effective date
Pet terms with deposit, pet rent and responsibility
Assigned parking
New occupant joining the lease
Utility changes
Space for any other term
Rule for conflicts with the lease
Clause that keeps the rest of the lease
What you fill in
Field
Example
Landlord
Cedar Grove Rentals
Tenant
Maya Johnson
Property
1209 Oak St, Unit B, Denver, CO
Lease date
August 1, 2026
Addendum type
Pet
Pet
One dog, Beagle, «Biscuit», 24 lb
Pet deposit
USD 300
Pet rent
USD 35 a month
How it gets signed
1Choose «Use this template», fill in the fields and review the full lease addendum.
2Send it by WhatsApp or email. The other party opens the link on their phone without an account.
3They tap the brown bar at the bottom that says «Sign as …» and draw their signature once.
4Everyone gets the signed PDF with its signature certificate. Anyone can check it at signsolu.com/verificar.
The signing screen tells each signer that signing means agreeing to sign electronically. It links to the electronic signature disclosure that the ESIGN Act asks for.
What you get once everyone signs
The signed PDF. The final lease addendum with every drawn signature in place.
The signature certificate. It lists each signer and the date and time of each signature.
A record you can check. The folio on the certificate opens the document history at signsolu.com/verificar.
Reminders. Turn them on and SignSolú reminds every signer who has not signed yet.
Your first ten documents are free and need no card.
What the law says
An addendum changes a contract, so it needs the agreement of everyone who signed the lease. A landlord cannot add terms alone during the lease term.
Some states limit pet deposits and fees or count them toward the security deposit limit. Assistance animals for people with disabilities are not pets under federal fair housing rules, and pet fees generally cannot be charged for them.
The ESIGN Act, 15 U.S.C. 7001 gives an electronic signature the same legal effect as one on paper. A contract cannot be denied effect only because it was signed electronically.
The exceptions in 15 U.S.C. 7003 cover some notices about a primary residence, such as eviction or default notices under a rental agreement. The lease itself can be signed electronically. Those notices follow your state rules on delivery.
Common lease addenda
Pet addendum for a new dog or cat.
Roommate addendum when someone joins the lease.
Parking addendum for an assigned space or garage.
Utility addendum when the landlord starts billing for water or trash.
Early termination addendum that sets a fee to end the lease early.
Lead-based paint disclosure for homes built before 1978.
Addendum or amendment
An addendum adds something new to the lease. An amendment changes something already there.
In practice, landlords use both words loosely. What matters is that the change is written and signed by everyone.
To change the end date, use a lease extension instead. It is clearer for both sides.
Writing a pet addendum
Describe each pet by type, breed, name and weight. A new pet needs a new addendum.
Set the pet deposit and pet rent within your state limits. Say the tenant pays for pet damage beyond the deposit.
Add rules for waste, leashes in common areas and noise. Neighbors complain about the same three things.
Common mistakes
Only one tenant signs. Every tenant on the lease signs the addendum.
No reference to the lease. Write the date and address of the original lease so the addendum is tied to it.
Charging pet fees for assistance animals. Federal fair housing rules treat them differently.
Signing an addendum in minutes
Addenda come up mid-lease, often by text. Answer with the addendum ready to sign.
The tenant signs from the phone. The signed addendum sits next to the lease with its certificate.
Keep your common addenda as templates. A pet request then takes a minute to answer with the right document.
Adding a new tenant mid-lease
Screen the new person the same way as the original tenants. Send a rental application first.
Once approved, use clause 2(c) to add them to the lease. Every current tenant and the new one sign the addendum.
Decide how the deposit is handled. Some landlords keep the original deposit and let the tenants settle shares among themselves.
Early termination addendum
An early termination addendum lets a tenant leave before the lease ends for a set fee and notice. It gives both sides a clear path.
Common terms are 30 to 60 days notice and a fee of one or two months rent. Some states set their own rules for situations like military orders or domestic violence.
Write the fee, the notice and the last day of rent in clause 2(e). A clear exit keeps the relationship friendly to the end.
Number each addendum and keep them with the lease in date order. The full set of signed documents shows the terms in force on any given day.
Before you sign
Read every clause of the lease addendum with the other party before anyone signs. Change what does not fit your deal.
