Can a supplemental charge be e-signed?

Yes. Electronic signatures are enforceable under the federal ESIGN Act (15 U.S.C. ch. 96) and UETA in most states, provided intent, consent, attribution, and record retention are met. Certain exceptions (e.g., wills) do not permit e-signatures.

Is notarization required for validity?

Not typically for simple commercial amendments, but state law or the original contract may require notarization for recordation or conveyance-related changes; verify with the relevant state or contract terms.

What if a party refuses to sign?

If the contract requires mutual agreement for amendments, unilateral imposition of charges risks breach and dispute; document communications and follow contractual notice and dispute procedures.

How should I handle partial payments?

Specify partial-payment schedules and consequences for nonpayment in the supplement; attach a revised invoice schedule and update accounting entries to match the new terms.

Does the supplement affect tax reporting?

Yes. Additional charges can change revenue recognition and information returns; ensure amounts are recorded in the correct tax period and reported according to IRS rules.

Can the supplement be revoked?

Revocation depends on contract language and mutual consent. To revoke, use a signed amendment or replacement document that expressly cancels the supplemental charge.

Electronic Signature
Templates
Legal
Supplemental Charge Agreement

Supplemental Charge Agreement

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SUPPLEMENTAL CHARGE AGREEMENT

This Supplemental Charge Agreement (the Agreement) is made effective as of by and between Client Name: and Service Provider Name: (each a Party and together the Parties).

RECITALS

WHEREAS, the Parties are parties to an existing agreement identified as Original Agreement Title: dated (the Original Agreement);

WHEREAS, the Parties desire to supplement the Original Agreement with one or more supplemental charges for services, materials, or work outside the Original Agreement’s scope, and to set forth the method of calculation, billing, and payment for such charges;

WHEREAS, the Parties intend that the terms of this Agreement shall control with respect to the supplemental charges described herein.

NOW, THEREFORE

In consideration of the mutual covenants contained herein and other good and valuable consideration, the receipt and sufficiency of which are acknowledged, the Parties agree as follows:

1. DEFINITIONS

1.1 "Supplemental Charge" means any additional fee or charge specifically described in Section 2 assessed by Provider to Client for goods or services performed outside the scope of the Original Agreement.

1.2 "Billing Cycle" means the recurring period for issuance of invoices for Supplemental Charges, as specified in Section 3.

2. SUPPLEMENTAL CHARGES

2.1 The Provider shall assess the Supplemental Charges described in the charge schedule below. Each listed charge shall be invoiced in accordance with Section 3. Provider represents that each charge is reasonable, reflects actual additional work or materials, and is calculated in accordance with the methodology stated for that charge.

Charge Schedule

Charge Item 1 — Description Charge Item 1 — Amount

Effective Date:

Charge Item 2 — Description Charge Item 2 — Amount

Effective Date:

Charge Item 3 — Description Charge Item 3 — Amount

Effective Date:

3. CALCULATION, INVOICING, AND BILLING

3.1 Provider shall calculate Supplemental Charges in accordance with the descriptions and amounts set forth in Section 2. Unless otherwise specified, charges shall be invoiced on a basis (the Billing Cycle).

3.2 Each invoice shall include a detailed statement showing the charge descriptions, quantities, unit prices, tax treatment, supporting references to services or materials performed, and the period to which the charges relate. Client shall have thirty (30) days from receipt of an invoice to notify Provider in writing of any disputed items. Failure to timely dispute shall constitute acceptance of the invoice.

3.3 Taxes: Unless otherwise indicated, amounts listed do include taxes exclude taxes . Client is responsible for all applicable sales, use, VAT, gross receipts or other similar taxes imposed on Supplemental Charges, except taxes based on Provider’s net income.

4. PAYMENT TERMS

4.1 Payment Terms: All undisputed invoices are due and payable within days from invoice date. Late payments shall accrue interest at a rate of or the maximum rate permitted by law, whichever is less.

4.2 Payment Dispute Procedure: For any disputed invoice or portion thereof, Client shall pay the undisputed portion in accordance with this Agreement. The Parties shall meet and confer in good faith to resolve disputes within thirty (30) days of Client’s notice of dispute.

5. ADJUSTMENTS AND CHANGE ORDERS

5.1 Any adjustment to a Supplemental Charge, including increases or decreases in scope, shall be effective only upon a written change order signed by authorized representatives of both Parties. Change orders shall specify the revised scope, adjusted charges, and any change to schedule or delivery obligations.

6. CONFIDENTIALITY

6.1 Each Party shall maintain in confidence all non-public information disclosed in connection with the Supplemental Charges and shall not disclose such information to any third party except as required by law or with the prior written consent of the disclosing Party. Confidential information shall be used solely for purposes of performing obligations under this Agreement.

7. INDEMNIFICATION; LIMITATION OF LIABILITY

7.1 Indemnification: Each Party shall indemnify, defend, and hold harmless the other Party from and against third-party claims arising from its gross negligence or willful misconduct in connection with the Supplemental Charges.

7.2 Limitation of Liability: Except for liability arising from gross negligence, willful misconduct, or a breach of confidentiality or indemnity obligations, neither Party shall be liable to the other for consequential, incidental, punitive, or special damages. Provider’s aggregate liability for any claim related to Supplemental Charges shall not exceed the total Supplemental Charges paid or payable under this Agreement for the twelve (12) months preceding the claim.

8. TERM AND TERMINATION

8.1 Term: This Agreement shall commence on the Effective Date set forth above and shall continue until all Supplemental Charges resulting from this Agreement have been invoiced and paid or until terminated earlier in accordance with this Section.

8.2 Termination for Cause: Either Party may terminate this Agreement for material breach by the other Party if such breach is not cured within thirty (30) days after receipt of written notice describing the breach. Termination shall not relieve Client of its obligation to pay for all Supplemental Charges incurred prior to termination.

9. NOTICES

All notices required or permitted under this Agreement shall be in writing and delivered to the addresses set forth below (or to such other address as a Party may designate by notice in accordance with this Section).

Client Notice Address Provider Notice Address

10. AMENDMENTS; WAIVER; COUNTERPARTS

10.1 Amendments: No amendment or modification of this Agreement shall be effective unless in writing and signed by authorized representatives of both Parties.

10.2 Waiver: No failure or delay by either Party in exercising any right under this Agreement shall operate as a waiver of that right, and any waiver must be in writing.

10.3 Counterparts: This Agreement may be executed in counterparts, each of which shall be deemed an original and all of which together shall constitute one instrument.

11. GOVERNING LAW; ENTIRE AGREEMENT; SEVERABILITY

11.1 Governing Law: This Agreement shall be governed by and construed in accordance with the laws of the State of without regard to its conflict of laws principles.

11.2 Entire Agreement: This Agreement, together with the Original Agreement (to the extent incorporated herein), constitutes the entire agreement between the Parties with respect to the subject matter hereof and supersedes all prior and contemporaneous agreements and understandings, whether written or oral, relating to such subject matter.

11.3 Severability: If any provision of this Agreement is held to be invalid, illegal or unenforceable in any respect, the validity, legality and enforceability of the remaining provisions shall not in any way be affected or impaired thereby.

SIGNATURES

The Parties, intending to be legally bound, have caused this Supplemental Charge Agreement to be executed by their duly authorized representatives as of the Effective Date.

Client Printed Name:

By:

Date:

Provider Printed Name:

By:

Date:

What a Supplemental Charge Agreement Is and when it applies

A Supplemental Charge Agreement documents adjustments or additions to charges after an original contract or invoice was issued. Typical uses include post-estimate change orders in construction, additional patient billing items in healthcare, or added service fees for professional engagements. The form records the reason for the additional charge, the amount, the effective date, and any payment or dispute terms. It operates as an amendment to the underlying contract and should reference the original agreement, identify the parties, and state whether the supplemental charge modifies payment schedule, scope, or deliverables.

Why use a Supplemental Charge Agreement

A clear supplemental agreement preserves evidence of consent to extra charges, reduces disputes, and documents revised obligations for accounting and compliance. It creates an auditable record that supports invoicing, collections, and regulatory reviews while clarifying payment timing and dispute rights.

Who commonly prepares and signs these agreements

Typical preparers include contracting parties, accounts receivable teams, project managers, and in-house counsel.

Construction contractors and subcontractors updating bids after change orders.
Healthcare providers documenting additional patient services or out-of-network charges.
Professional services firms adding scope-driven fees during project delivery.

Use by these groups helps ensure consistent billing, regulatory traceability, and clearer dispute resolution.

Essential elements to include in a professional Supplemental Charge Agreement

A well-drafted agreement is concise but specific, tying the supplemental charge to the original contract and describing payment and dispute processes.

Reference

Identify the original contract or invoice by title, date, and reference number so the amendment links unambiguously to prior obligations.

Charge Details

State the additional charge amount, whether it is a lump sum or itemized, and whether taxes, fees, or retainage apply to the supplemental amount.

Effective Date

Specify the date the supplemental charge takes effect and whether it applies retroactively to prior performance or to future work only.

Payment Terms

Describe payment timing, acceptable payment methods, late fees, and whether the charge affects existing milestones or retainers.

Authorization

Include signature blocks, printed names, titles, and capacity statements to confirm signatory authority and consent.

Dispute Process

Outline notice requirements, cure periods, escalation steps, and the governing law or venue for resolving disagreements.

Required data fields for accuracy and enforceability

Parties: Full legal names

Reference ID: Original contract number

Effective Date: MM/DD/YYYY

Charge Amount: USD amount

Payment Terms: Net days

Signatures: Signed & dated

Step-by-step: completing a Supplemental Charge Agreement

Follow these steps to create a clear, enforceable amendment and reduce processing friction.

01

Identify contract: Locate original agreement and reference number.
02

Describe change: State added work or charge reason concisely.
03

Set terms: Define amount, payment schedule, and late fees.
04

Obtain signatures: Collect authorized signatures with dates.

Configuring an online workflow for completion and approval

Map fields and routing so the agreement moves automatically from preparer to approver and to accounts receivable for invoicing.

Field	Configuration
Reference ID field	Required; validate against contract database
Amount field	Numeric only; two decimal places
Signature block	Required signer; date stamp enabled
Approval route	Project manager then finance approver

Where to send the completed agreement

Route completed agreements to the right recipients for records and billing; record an audit trail for future reference.

Signatories: Primary and counterparty sign and date.
Accounts Receivable: Attach to invoice processing queue.
Project File: Store with original contract documents.
Legal/Compliance: Send copy for contract repository review.

Digital signing and distribution considerations

Choose a platform that supports secure eSignatures, audit trails, and the integrations your teams use.

File formats: PDF, DOCX supported
Integrations: Salesforce, NetSuite, Google Workspace
Authentication: Email OTP, SMS code, or KBA

Ensure the platform can capture timestamps, signer attribution, and a tamper-evident final file for retention and audit.

Typical timing and processing expectations

Timelines vary by industry and contract terms; use these typical timing guidelines when scheduling invoicing and dispute windows.

Submission window:

Submit supplemental charges promptly; many contracts require notice within 30 days.

Payment due date:

Follow the payment terms in the amendment (commonly Net 30).

Dispute notice:

Allow the other party reasonable cure period—often 15–30 days.

Accounting entry:

Record the change in the same period that the charge was accepted.

Audit retention:

Keep a signed copy with the contract file for required retention periods.

Common preparation errors to avoid

Failing to reference the original contract clearly, which creates ambiguity about the scope the supplemental charge is intended to modify.
Missing or unsigned authorization lines that can render the supplemental agreement unenforceable or delay collections.
Using vague language for charge reasons or amounts instead of itemized descriptions that finance and auditors require.
Not routing the signed amendment to accounts receivable and legal, causing invoicing or compliance gaps.

Consequences of an incorrect or incomplete Supplemental Charge Agreement

Contract invalidity: Court may refuse enforcement

Payment disputes: Delays or refusal to pay

Audit findings: Accounting adjustments required

Tax implications: Incorrect reporting risk

Regulatory risk: Industry-specific penalties

Collection costs: Added legal or recovery fees

eSignature vendor comparison for managing Supplemental Charge Agreements

Compare core pricing and feature availability for common eSignature platforms; signNow is listed first per product data and plan structure.

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

Practical examples of Supplemental Charge Agreements in use

Two concise examples show how a supplemental agreement clarifies billing and reduces disputes.

Construction Change Order

A contractor documents a $12,500 scope increase after unforeseen site conditions

Change order references original bid and adds Net 30 payment terms
The signed supplement prevented a stop-work notice and supported timely invoice processing with the owner and lender.

Healthcare Billing Adjustment

A clinic records an out-of-network service added after initial intake

The supplement itemizes the service and patient responsibility
Having written acknowledgment reduced billing disputes and provided clear documentation for insurance appeals.

Frequently asked questions about Supplemental Charge Agreements

Answers to common questions about drafting, signing, and enforcing supplemental charge amendments.

Need help? Contact support

Can a supplemental charge be e-signed?
Yes. Electronic signatures are enforceable under the federal ESIGN Act (15 U.S.C. ch. 96) and UETA in most states, provided intent, consent, attribution, and record retention are met. Certain exceptions (e.g., wills) do not permit e-signatures.
Is notarization required for validity?
Not typically for simple commercial amendments, but state law or the original contract may require notarization for recordation or conveyance-related changes; verify with the relevant state or contract terms.
What if a party refuses to sign?
If the contract requires mutual agreement for amendments, unilateral imposition of charges risks breach and dispute; document communications and follow contractual notice and dispute procedures.
How should I handle partial payments?
Specify partial-payment schedules and consequences for nonpayment in the supplement; attach a revised invoice schedule and update accounting entries to match the new terms.
Does the supplement affect tax reporting?
Yes. Additional charges can change revenue recognition and information returns; ensure amounts are recorded in the correct tax period and reported according to IRS rules.
Can the supplement be revoked?
Revocation depends on contract language and mutual consent. To revoke, use a signed amendment or replacement document that expressly cancels the supplemental charge.

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