Contract Addendum
Add, change, remove or clarify terms in a contract that is already signed, without rewriting the whole agreement.
Includes 30 days of edits
- 5 to 20 minutes
- Print-ready PDF
What is a Contract Addendum?
A contract addendum is a short document that the parties to an existing contract sign to add new terms or change the terms they already agreed. It refers back to the original contract by name and date, sets out each change precisely, and confirms that every other part of the original contract stays the same.
People use the words addendum and amendment loosely. Strictly speaking, an addendum adds something new, such as an extra service, a new deliverable or a schedule, while an amendment changes or deletes wording that is already there. In practice, a single well-drafted addendum can do both, as long as each change is clearly identified by section number and the new wording is written out in full.
This document lets you list as many changes as you need, choose whether each one adds, replaces, deletes or clarifies a provision, and state when the changes take effect. It includes the standard protections that keep an addendum from creating confusion: a conflict rule saying the addendum controls, a confirmation that the original contract is otherwise unchanged, and signature blocks for every party.
When to use it
- You and the other party agreed to extend the term, change the price or adjust the payment schedule of a signed contract.
- You need to add a new service, product, deliverable or location to an existing agreement.
- A clause in the contract turned out to be unclear and both sides want to agree on what it means.
- You want to remove a provision that no longer applies, such as an expired discount or a cancelled phase.
- A party's name, address or contact person has changed and the contract should reflect it.
What is included
- Identification of the parties and the original contract
- List of earlier amendments or addenda, if any
- Each change, labeled as an addition, replacement, deletion or clarification
- Effective date of the changes
- Optional payment or other consideration for the changes
- Conflict rule giving the addendum priority
- Confirmation that all other terms remain in force
- Governing law consistent with the original contract
- Signature blocks for individuals or business signers
- Optional notary acknowledgment
How to make your Addendum
Answer the questions
Tell us about the parties and the terms you want. Most documents take about 5 to 20 minutes.
Review the preview
Check the draft as you go and change any answer. The document updates instantly.
Download, sign and keep a copy
Download a print-ready PDF, sign it with the other parties, and give everyone a copy.
Frequently asked questions
What is the difference between an addendum and an amendment?
An addendum usually adds new terms to a contract, while an amendment changes or deletes terms that are already there. Many people use the words interchangeably, and this document handles both: each change you list can be an addition, a replacement, a deletion or a clarification.
Does an addendum need to be signed by both parties?
Yes. A change to a contract is generally binding only if everyone who signed the original agreement agrees to it. Each party, or an authorized signer for a business, should sign the addendum. Many contracts also say that changes are valid only in a signed writing.
Can I add an addendum after the contract is signed?
Yes. That is what an addendum is for. An addendum can also be signed at the same time as the main contract to attach extra terms, such as a schedule, but this document is designed for changing an agreement that is already in place.
What happens if the addendum conflicts with the original contract?
This addendum states that its terms control if there is a conflict. Everything in the original contract that the addendum does not change stays in effect exactly as written.
Do I need to pay anything for an addendum to be valid?
Not always. In many cases the parties' new mutual promises are enough. Some states still require consideration for certain changes, so the document lets you record a payment or other exchange when there is one, and recites that each party receives value from the changes.
How should I describe the changes?
Refer to the exact section number of the original contract, say whether you are adding, replacing, deleting or clarifying it, and write the new wording out in full. Avoid vague language like "the price will be adjusted"; give the new number and the date it applies.
Should an addendum be notarized?
Usually not. It needs the same formalities as the original contract, so if the original was notarized or recorded, for example a real estate document, the addendum may need to be notarized too. You can add a notary acknowledgment when you answer the questions.
Can I use this to change a residential lease?
A lease amendment is designed specifically for leases and handles landlord-tenant rules better. Use this general addendum for business and service contracts, purchase agreements and other commercial arrangements.
