wikiHow Example Contract Addendum Letter [Your Name] [Your Address] [City, State, ZIP] [Email Address] [Phone Number] [Date] [Recipient's Name] [Recipient's Address] [City, State, ZIP] Subject: Addendum to [Contract Title or Number] Dear [Recipient's Name], I hope this letter finds you well. This addendum serves as an extension and modification to the existing contract [Contract Title or Number] dated [Contract Date] between [Your Name] (hereinafter referred to as "Party A") and [Recipient's Name] (hereinafter referred to as "Party B"). Both parties mutually agree to the following terms and conditions: Amendment of Contract Duration: The original contract duration of [Contract Duration] is hereby extended for an additional period of [Extension Duration], commencing from [New Start Date] and ending on [New End Date]. All other terms and conditions of the original contract shall remain unchanged. Modification of Payment Terms: The payment terms stated in the original contract are hereby revised as follows: [Specify the revised payment terms, including changes to payment schedule, amounts, or methods.] Additional Scope of Work: Party B agrees to undertake additional tasks or provide additional services as follows: [Clearly specify the additional scope of work, including deliverables, timelines, and any associated costs, if applicable.] Governing Law: This addendum shall be governed by and construed in accordance with the laws of [Governing Law Jurisdiction]. Any disputes arising from or related to this addendum shall be subject to the exclusive jurisdiction of the courts in [Jurisdiction]. Entire Agreement: This addendum, together with the original contract, constitutes the entire agreement between the parties and supersedes any prior understandings or agreements, whether written or verbal, relating to the subject matter herein. Please review and sign this addendum to indicate your acceptance of the proposed modifications. Kindly return a signed copy to [Your Name] no later than [Agreement Deadline]. We appreciate your attention to this matter. Should you have any questions or require further clarification, please do not hesitate to contact me at [Your Email Address] or [Your Phone Number]. Thank you for your cooperation. We look forward to continuing our mutually beneficial business relationship. Sincerely, [Your Name] [Your Title/Position] [Your Company Name] Page