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Add-On Service Agreement

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ADD-ON SERVICE AGREEMENT

This Add-On Service Agreement ("Agreement") is made effective as of by and between:

Client Name:    Client Address:

Service Provider Name:    Provider Address:

RECITALS

WHEREAS, Client and Service Provider are parties to a primary services agreement under which Service Provider provides certain base services to Client (the "Primary Agreement"); and

WHEREAS, Client desires to procure and Service Provider agrees to provide the additional or ancillary services described in this Agreement as an add-on to the Primary Agreement; and

WHEREAS, the Parties intend for this Agreement to set forth the scope, payment terms, and other material terms applicable to such add-on services.

SCOPE OF WORK

The Provider shall furnish the add-on services described above in a professional and workmanlike manner consistent with industry standards. Any material change to the Scope of Work shall require prior written agreement signed by both Parties.

PAYMENT TERMS

Invoices shall be submitted by Service Provider in accordance with the payment schedule above and are due within days of receipt unless otherwise agreed in writing.

Late Fee: Unpaid amounts shall accrue interest at the lesser of (a) a rate of per month, or (b) the maximum rate permitted by law, plus a one-time administrative late payment fee of .

All payments shall be made in lawful currency to the account designated by Service Provider. Client is responsible for any taxes (other than taxes based on Provider's net income) arising from the fees payable under this Agreement.

TERM AND TERMINATION

Term Commencement Date: .    Term Expiration Date: .

Either Party may terminate this Agreement for convenience upon days' prior written notice to the other Party. Either Party may terminate this Agreement immediately for material breach by the other Party if such breach is not cured within days after written notice of the breach.

Upon termination, Client shall pay Provider for all services performed and authorized expenses incurred through the effective date of termination. Sections relating to confidentiality, payment of accrued amounts, limitation of liability, and governing law shall survive termination.

CONFIDENTIALITY

"Confidential Information" means all non-public information disclosed by one Party to the other that is identified as confidential or that reasonably should be understood to be confidential given the nature of the information. The receiving Party shall: (a) maintain Confidential Information in strict confidence; (b) use Confidential Information solely to perform its obligations under this Agreement; and (c) not disclose Confidential Information to any third party except to its employees, agents, or contractors who have a need to know and who are bound by confidentiality obligations at least as protective as those set forth herein.

Confidentiality obligations shall not apply to information that is: (i) publicly known through no wrongful act of the receiving Party; (ii) rightfully received from a third party without restriction; (iii) independently developed by the receiving Party without use of Confidential Information; or (iv) required to be disclosed by law, provided that the receiving Party gives the disclosing Party prompt written notice and cooperates in seeking protective relief.

INDEPENDENT CONTRACTOR; ASSIGNMENT

Service Provider is an independent contractor. Nothing in this Agreement creates an employment, partnership, joint venture, or agency relationship between the Parties. Neither Party may assign this Agreement without the other Party's prior written consent, except that Provider may assign this Agreement to an affiliate or in connection with a sale of substantially all of its assets.

LIMITATION OF LIABILITY

Except for liability arising from a Party's gross negligence, willful misconduct, or breach of confidentiality, in no event shall either Party be liable for indirect, incidental, consequential, special, or punitive damages. The total aggregate liability of each Party for any claim arising from or relating to this Agreement shall not exceed the total fees paid or payable by Client to Provider under this Agreement during the six (6) months preceding the date the claim arose.

GOVERNING LAW; DISPUTE RESOLUTION

This Agreement shall be governed by and construed in accordance with the laws of the State of , without regard to conflicts of law principles. The Parties shall attempt in good faith to resolve disputes promptly by negotiation between executives. If the Parties cannot resolve a dispute within 30 days, the dispute shall be resolved by binding arbitration conducted in accordance with commercially reasonable procedures mutually agreed by the Parties.

ENTIRE AGREEMENT

This Agreement, together with the Primary Agreement and any documents expressly incorporated herein, constitutes the entire agreement between the Parties with respect to the subject matter hereof and supersedes all prior and contemporaneous agreements, understandings, negotiations and discussions, whether oral or written. No amendment to this Agreement is effective unless in writing and signed by authorized representatives of both Parties.

MISCELLANEOUS

If any provision of this Agreement is found to be invalid or unenforceable, the remaining provisions shall continue in full force and effect. The waiver of any breach shall not constitute a waiver of any subsequent breach. The Parties acknowledge that monetary damages may be inadequate and that injunctive relief may be awarded in addition to other remedies.

Client:

By:

Date:

Service Provider:

By:

Date:

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What an Add-On Service Agreement Is and When It Applies

An Add-On Service Agreement is a written contract that extends, modifies, or supplements an existing master services agreement or primary contract to cover additional services, scope changes, or new deliverables. It typically identifies the parties, describes the added services or features, sets pricing or payment terms for the add-on work, defines an effective date and term, and confirms that all other terms of the original agreement remain in force except as expressly changed. Organizations use add-on agreements to document incremental work without redrafting the entire base contract, providing a clear record of approvals and financial adjustments.

Why Use a Formal Add-On Service Agreement

A formal add-on agreement reduces ambiguity by documenting approved changes to scope, price, or schedule and creates an auditable record for billing and compliance. When electronically executed, it meets U.S. legal standards for e-signatures under the ESIGN Act (15 U.S.C. §7001) and most state UETA statutes, provided intent, consent, attribution, and retention requirements are satisfied.

Why Use a Formal Add-On Service Agreement

Who Typically Prepares and Signs Add-On Service Agreements

Assign a single point of ownership for approvals and maintain the signed add-on with the original contract to ensure consistent interpretation and audit readiness.

  • Procurement leaders and contracts teams who must track amendments and cost changes in a vendor relationship.
  • Project managers and account owners who need written approval for scope expansions or accelerated delivery.
  • Company officers or delegated signatories with contract authority to bind the organization.

Who Can Sign and Why Their Role Matters

Authorized Officer

An officer with board- or charter-granted contracting authority should sign when the add-on changes financial commitments. Their signature ensures enforceability and internal compliance with delegated authority policies.

Delegated Signatory

A manager with written delegation (POA or internal policy) may sign for operational changes under a threshold. Confirm delegation exists and retain the delegation document with the add-on for audit trails.

Information Fields Required in an Add-On Service Agreement

Effective Date: MM/DD/YYYY
Parties: Legal entity names
Scope Description: Concise service summary
Pricing: Fees or rate schedule
Term: Start and end date
Signature Block: Signer name and title

Step-by-Step: How to Complete an Add-On Service Agreement

Follow these steps to prepare, review, and execute an add-on agreement so it aligns with the base contract and is enforceable.

  • 01
    Identify base contract: Reference original agreement by title and effective date.
  • 02
    Describe add-on: Clearly state new services, deliverables, or exclusions.
  • 03
    Set compensation: List fees, invoicing schedule, and payment terms.
  • 04
    Obtain signatures: Get authorized signatures and dates from all parties.

How to Configure an Electronic Workflow for an Add-On

Set up a simple signer flow that mirrors your internal approval path and preserves an audit trail.

Field Configuration
Upload Document PDF or DOCX preferred
Assign Signers Role-based order or parallel
Authentication Email + optional SMS code
Retention Setting Enable audit trail and PDF certificate

Where to Send the Completed Add-On and How It Is Processed

A consistent routing process saves time and prevents disputes; map recipients and archival locations before sending.

  • Internal Approvals: Send to legal and finance for signoff before external circulation.
  • External Recipient: Email signer or provide a secure signing link.
  • Execution: Collect signatures and timestamps electronically.
  • Archive: Store signed copy with the base contract record.

Distribution and Digital Signing Options

Preserve the audit trail and signed PDF; when HIPAA or higher assurance is required, apply stronger signer authentication and retain verification artifacts.

  • In-Person: Wet signature with local notary
  • eSignature: Email link or hosted signing page
  • RON: Remote notarization via audio-video

Key Clauses to Include in a Professional Add-On Service Agreement

Include clear, standalone clauses so the add-on can be read with the base contract. The following six items reduce interpretive risk and support enforceability.

Scope of Work

A precise description of new services, deliverables, acceptance criteria, and any excluded items to prevent scope creep and billing disputes.

Pricing and Payment

Detailed fees, invoicing schedule, tax allocation, and consequences for late payment or disputed invoices.

Term and Termination

Start and end dates, renewal mechanics, termination for convenience and for cause, and post-termination obligations.

Integration Clause

Statement that all unchanged provisions of the base agreement remain effective except where the add-on expressly modifies them.

Change Control

Procedure for future adjustments, including approval signatures and budget change caps to control scope changes.

Signatory Authority

Representation that signers have authority to bind their respective entities and that any required internal approvals are complete.

Supporting Elements and File Formats to Include

Attach or reference supporting materials to make the add-on immediately operational and auditable without returning to the base agreement.

Schedules

Attach milestone schedules, delivery dates, and acceptance checklists so obligations and measurement criteria are unambiguous and machine-readable when possible.

Pricing Appendix

Include a fee table or cost worksheet showing unit pricing, quantity, and total sums to reduce billing disputes and simplify accounting entries.

Change Log

A recorded history of amendments and approvals that links each change to an authorizing person or PO for auditability.

Format Recommendations

Use PDF/A for long-term archive and keep an editable DOCX copy for internal change tracking; ensure signed PDFs embed the audit trail.

Timelines and Typical Deadlines to Track

Track key dates so deliverables, invoicing, and dispute windows are clear to all parties.

Effective Date:

Date obligations and billing commence; use MM/DD/YYYY format.

Milestone Dates:

List each deliverable due date and acceptance period for invoice triggers.

Invoicing Cycle:

State invoice submission and payment terms (e.g., Net 30).

Termination Notice:

Number of days required for termination notice per clause.

Record Retention:

How long signed add-ons are retained for audit and tax.

Common Mistakes When Preparing an Add-On

  • Failing to reference the base agreement precisely, causing disputes about which terms apply and which are superseded.
  • Vague scope language that omits acceptance criteria, enabling conflicting expectations about deliverables or quality.
  • Missing or incorrect signer authority, which can render the add-on unenforceable or prompt repudiation.
  • Neglecting to update pricing tables or invoicing instructions, leading to delayed payments and accounting reconciliation issues.

Risks and Consequences of an Incorrect or Missing Add-On

Breach Claims: Contract disputes
Payment Delays: Revenue impact
Regulatory Exposure: Compliance fines
Audit Failures: Recordkeeping penalties
Enforceability: Signature challenges
Operational Delay: Project stoppage

How an Add-On Service Agreement Differs from Related Documents

Compare common templates to determine whether an add-on, amendment, SOW, or change order is the correct instrument for your change.

Document Type Add-On Amendment Statement of Work
Purpose adds services modifies terms details deliverables
Formality moderate high moderate
Signatures Required
Typical Use additional services contract term changes project specs

eSignature Vendor Comparison for Executing Add-On Agreements

Platform choice affects per-user cost, bulk sending, HIPAA coverage, and envelope caps; compare core pricing and compliance features below.

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 trial Varies Varies Varies Varies
Bulk Send Yes Varies Varies Varies Varies
Audit Trail Yes Yes Yes Yes Yes
HIPAA Compliant Yes Yes Yes No No
Envelope Cap No cap 100 envelopes/user/year Varies Varies Varies

Real-World Examples of Add-On Agreements

These short examples illustrate typical business scenarios where an add-on agreement is appropriate.

Marketing Campaign Expansion

A client requests additional deliverables beyond the original monthly campaign scope.

  • The add-on lists new channels, KPIs, and extra fees.
  • The signed add-on enables immediate work, ties invoicing to the added scope, and prevents disputes about which activities are billable.

Feature Development for Software

A customer requests a paid feature outside the existing roadmap.

  • The add-on defines acceptance tests and delivery milestones.
  • With the add-on in place, development begins after sign-off and payments are invoiced per milestone, reducing late-payment disputes.

Frequently Asked Questions About Add-On Service Agreements

Answers to common legal, procedural, and technical questions about drafting, signing, and storing add-on agreements.


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