Can an addendum change all PSA terms?

Yes, but only to the extent the addendum explicitly amends those terms; unchanged provisions of the PSA remain in force. Use clear cross-references and consider restating amended clauses to avoid interpretive disputes.

Is notarization required for the addendum?

Generally no for commercial contract amendments; however, specific states or particular subject matter (e.g., assignment of property interests) can require notarization or witnesses—verify state rules before execution.

Are electronic signatures valid?

Electronic signatures are generally valid under the ESIGN Act (15 U.S.C. ch. 96) and UETA where adopted; ensure intent, consent, attribution, and reliable record retention to meet legal validity tests.

Who should sign the addendum?

Authorized corporate representatives with actual authority should sign. Verify authority via corporate resolution or delegated signing policy to prevent later challenges to enforceability.

What if parties disagree after signing?

Follow the dispute resolution clause in the PSA or addendum; preserve all correspondence, audit logs, and acceptance records, and consult legal counsel for mediation or litigation options.

How should executed addenda be stored?

Store signed PDFs with audit trails in secure, access-controlled repositories and follow retention timelines tied to tax, HIPAA, or other regulatory requirements to preserve evidentiary value.

Electronic Signature
Templates
Project Management
Project Management PSA Addendum

Project Management PSA Addendum

This template is fully customizable. Edit the text, fill out the fields, and send it for signature. Give it a try!

PROJECT MANAGEMENT PSA ADDENDUM

Addendum No.: Effective Date:

Project Identification

Project ID Project Title Client Name Service Provider Project Manager (Client) Project Manager (Service Provider)

Recitals

This Project Management Professional Services Agreement Addendum ("Addendum") is made between Client: and Service Provider: .

WHEREAS, the parties entered into a Professional Services Agreement dated: (the "Agreement"); and

WHEREAS, the parties desire to amend the Agreement as set forth in this Addendum pursuant to the Agreement's amendment provisions.

Amendments to Scope of Work

New Scope of Work (Describe additional tasks, responsibilities, and deliverables) Out-of-Scope Items (Specific exclusions)

Deliverables and Acceptance Criteria

Deliverable 1 — Description:

Acceptance Criteria

Due Date:

Deliverable 2 — Description:

Acceptance Criteria

Due Date:

Timeline and Milestones

Project Start Date: Project End Date:

Milestone 1 (Description)

Milestone 1 Date:

Milestone 2 (Description)

Milestone 2 Date:

Budget, Fees and Payment

Total Additional Compensation Payment Schedule (Describe installments, milestones, or retainers) Installment 1 Amount

Due Date:

Installment 2 Amount

Due Date:

Change Order Process

All modifications to scope, schedule, or price shall be implemented only by a written Change Order executed by authorized representatives of both parties. Change orders shall describe the change, identify impacts on cost and schedule, and be signed prior to commencement of changed work.

Change Order Authorization Contact (Client) Change Order Authorization Contact (Service Provider)

Confidentiality

The parties agree that all information exchanged in connection with this Addendum that is marked confidential or would reasonably be considered confidential shall be held in confidence for a period of years from disclosure. Each party shall use no less than reasonable care to protect Confidential Information and shall not disclose it to third parties except as required by law or as necessary to perform the obligations under this Addendum.

Intellectual Property; Work Product

All deliverables specifically created for Client under this Addendum shall be considered Work Product. Unless otherwise agreed in writing, Service Provider hereby assigns to Client all right, title and interest in Work Product upon full payment; Service Provider retains the right to use general knowledge, skills, and methodologies. To the extent any underlying pre-existing materials of Service Provider are incorporated into Work Product, Service Provider grants Client a perpetual, non-exclusive, worldwide license to use such materials as part of the Work Product.

Limitation of Liability; Insurance

Except for liability resulting from gross negligence, willful misconduct, or breach of confidentiality, neither party shall be liable to the other for indirect, consequential, special, or punitive damages. The aggregate liability of a party for claims arising from this Addendum shall be limited to the total fees actually paid to Service Provider under this Addendum.

Termination

Either party may terminate this Addendum for material breach if the breach remains uncured for thirty (30) days after written notice. Upon termination, Client shall pay Service Provider for all work performed and reasonable wind-down costs incurred through the effective date of termination, subject to any offsets permitted by the Agreement.

Notices

Client Notice Address Service Provider Notice Address

Governing Law; General Provisions

This Addendum shall be governed by and construed in accordance with the laws of the State of without regard to conflict of laws principles. Except as expressly modified herein, the Agreement remains in full force and effect. This Addendum, together with the Agreement, constitutes the entire agreement between the parties with respect to the subject matter herein and supersedes all prior understandings.

Acceptance of Addendum

By signing below, the parties acknowledge that they have read, understood, and agree to be bound by the terms of this Addendum. This Addendum becomes effective on the Effective Date set forth above.

Client:

By:

Date:

Title:

Service Provider:

By:

Date:

Title:

What the Project Management PSA Addendum Is and when it applies

A Project Management PSA Addendum is a contract amendment appended to a Professional Services Agreement (PSA) that defines project-specific scope, deliverables, schedule changes, acceptance criteria, and allocation of project management responsibilities. It documents modifications or clarifications that are narrower than a full PSA renegotiation but legally alter the base agreement between parties. The addendum typically references the original PSA by date and section, sets an effective date, and records signatures or electronic sign-offs from authorized representatives of each party to bind the amendment to the original contract.

Why add a Project Management PSA Addendum to an existing PSA

An addendum creates a concise, enforceable record of project-specific changes—reducing disputes about scope or timelines, aligning stakeholders on responsibilities, and preserving the original PSA terms except where explicitly modified.

Typical stakeholders who prepare or sign this addendum

Teams preparing or approving a Project Management PSA Addendum usually include project managers, contracting or legal staff, procurement, and client account owners; signatures should come from authorized signatories.

Project Managers and PMO: Draft scope, milestones, dependencies, risk owners, and change control procedures; ensure technical accuracy and schedule feasibility.
Procurement / Contracts: Verify alignment with commercial terms, pricing adjustments, and liability caps; confirm any needed approvals.
Client Account or Sponsor: Confirm acceptance criteria, deliverable dates, and billing triggers; provide final sign-off authority.

Use the addendum to document agreed changes quickly and retain it with the original PSA; ensure all signatories have authority before execution.

Step-by-step: completing a Project Management PSA Addendum

Follow these steps to create a clear, enforceable addendum that amends the PSA without ambiguity.

01

1. Reference Original: Identify the PSA by title, date, and section numbers being modified.
02

2. Define Scope: Describe deliverables, milestones, and work excluded from the change.
03

3. Update Schedule: Specify new milestone dates, duration, and any acceptance windows.
04

4. Sign and Date: Obtain authorized signatures and record the effective date.

Configuring an online workflow for the addendum

Recommended settings for digitizing the addendum and routing it to stakeholders for review and signature.

Field	Configuration
Document Template	Use a PDF template with fillable fields and version number
Signer Order	Set sequential signing when approvals must follow hierarchy
Authentication	Require email + SMS code for external clients to strengthen attribution
Retention	Enable automatic archive to secure storage with audit log

Digital signing and submission requirements

Choose an eSignature platform that supports secure signer authentication, audit trails, and exportable signed PDFs for the contract record.

Authentication: Email + optional SMS or KBA
Document Formats: PDF, DOCX supported
Integrations: CRM and cloud storage integrations

Ensure the platform you select can meet legal and compliance requirements for the parties involved, produce a tamper-evident signed PDF, and retain an audit trail that documents attribution, timestamps, and IP addresses.

Typical e-signing flow for an addendum

A standard online signing workflow reduces turnaround and preserves an evidentiary audit trail for contract amendments.

Upload Document: Sender uploads the addendum and places required fields.
Add Signers: Enter signer emails and set role-based permissions.
Authentication: Choose SMS or email authentication as needed.
Execute & Archive: Signed document and certificate are stored with audit trail.

Core components to include in a professional addendum

Include the following elements to ensure the addendum is precise, enforceable, and operationally useful for project teams and legal reviewers.

Reference Clause

Explicitly identify the PSA section(s) being modified and state that all other terms remain in force unless changed by this addendum.

Scope Definition

Provide a concise description of the added or changed work, including deliverable formats and any items explicitly excluded from scope.

Schedule & Milestones

List updated milestone names, deliverable dates, dependencies, and acceptance criteria tied to each milestone.

Pricing and Payment

State any price adjustments, invoicing milestones, payment terms, and whether rates are fixed or time-and-materials.

Change Control

Describe the process for further modifications, including approvals required and how cost/time impacts will be handled.

Signatures

Provide signature blocks for authorized signatories, titles, company names, and dates; indicate if electronic signatures are acceptable.

Essential data fields to capture on the addendum

Addendum Title: Clear identifier

PSA Reference: Original PSA date

Effective Date: MM/DD/YYYY format

Scope Summary: Brief change description

Signatory Details: Name, title, company

Approval Trace: Audit trail retained

Common legal and commercial risks

Unauthorized Signatures: Ultra vires risk

Vague Scope: Dispute over deliverables

Missing Dates: Unclear effective period

Billing Discrepancies: Invoice disputes

Noncompliance: Regulatory exposure

Retention Failures: Lost audit evidence

Errors to watch for when preparing the addendum

Not tying the addendum to the correct PSA by date or identifier, which creates uncertainty about which master agreement is modified.
Using ambiguous language for scope or deliverables that permits multiple reasonable interpretations and invites disputes.
Failing to update milestone dependencies, leaving teams unaware of downstream schedule impacts and acceptance conditions.
Signing without verifying authority, which may render the addendum unenforceable and require re-execution with proper approvals.

Key timeline and deadline considerations for addenda

Track effective dates, acceptance periods, invoicing triggers, and legal deadlines to avoid performance or payment disputes.

Effective Date:

Set and record as MM/DD/YYYY to start new obligations

Acceptance Window:

Define duration for deliverable review and acceptance

Invoice Trigger:

Specify when invoices may be issued after milestone acceptance

Dispute Notice:

Set deadline for notifying defects or nonconformance

Record Retention:

Document storage period tied to retention policy

eSignature vendor comparison for executing the addendum

Comparison of common eSignature criteria; signNow is shown first as a platform option that supports required features for contract addenda execution.

	signNow	DocuSign	Adobe Sign	PandaDoc	HelloSign
Starting Price	$8/user/mo	$15/user/mo	$14/user/mo	$19/user/mo	$15/user/mo
Free Trial	7-day free trial	Varies by vendor	Varies by vendor	Varies by vendor	Varies by vendor
Bulk Send	Yes (Business Premium)	Varies	Varies	Varies	Varies
Audit Trail	Yes	Yes	Yes	Yes	Yes
HIPAA Compliant	Yes (BAA available)	Yes	Yes	No	No
Envelope Cap	No cap	100 envelopes/user/year	Varies	Varies	Varies

Frequently asked questions about Project Management PSA Addenda

Answers to common questions about preparation, execution, and enforceability of a PSA addendum.

Need help? Contact support

Can an addendum change all PSA terms?
Yes, but only to the extent the addendum explicitly amends those terms; unchanged provisions of the PSA remain in force. Use clear cross-references and consider restating amended clauses to avoid interpretive disputes.
Is notarization required for the addendum?
Generally no for commercial contract amendments; however, specific states or particular subject matter (e.g., assignment of property interests) can require notarization or witnesses—verify state rules before execution.
Are electronic signatures valid?
Electronic signatures are generally valid under the ESIGN Act (15 U.S.C. ch. 96) and UETA where adopted; ensure intent, consent, attribution, and reliable record retention to meet legal validity tests.
Who should sign the addendum?
Authorized corporate representatives with actual authority should sign. Verify authority via corporate resolution or delegated signing policy to prevent later challenges to enforceability.
What if parties disagree after signing?
Follow the dispute resolution clause in the PSA or addendum; preserve all correspondence, audit logs, and acceptance records, and consult legal counsel for mediation or litigation options.
How should executed addenda be stored?
Store signed PDFs with audit trails in secure, access-controlled repositories and follow retention timelines tied to tax, HIPAA, or other regulatory requirements to preserve evidentiary value.

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