Are electronic signatures valid on addenda

Yes. Electronic signatures are legally enforceable under the ESIGN Act (15 U.S.C. §7001) and UETA where adopted, provided the transaction meets intent, consent, attribution, and record retention requirements.

When is notarization required

Notarization is generally not required for LOI addenda, but certain jurisdictions or lenders may demand notarized acknowledgements; verify state or contractual requirements before execution.

What if a signer lacked authority

If an individual lacked authority, the amendment may be voidable; attach board resolutions or powers of attorney to evidence authority and reduce challenge risk.

How do I correct a signed addendum

Prepare a second addendum stating the correction and have authorized signers execute it; avoid handwritten changes without full re-execution to prevent ambiguity.

Can an addendum change material terms

Yes; an addendum can modify material terms if parties consent and authorized signatories execute it, but substantial changes may require renegotiation or a replacement agreement.

How long should I retain the addendum

Retain the executed addendum with the original LOI for the active term plus applicable retention periods: at least 3 years for tax records and up to 6 years for HIPAA-related documents.

Electronic Signature
Templates
Legal
Legal LOI Addendum

Legal LOI Addendum

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LEGAL LOI ADDENDUM

This Addendum to the Letter of Intent (the "Addendum") is made effective as of by and between First Party: whose address is and Second Party: whose address is .

RECITALS

WHEREAS, the parties entered into a Letter of Intent dated (the "LOI"), which described certain terms and conditions governing the proposed transaction between the parties;

WHEREAS, the parties desire to amend and clarify certain provisions of the LOI and to set forth additional terms and conditions to which they have agreed;

WHEREAS, capitalized terms used but not defined in this Addendum shall have the meanings ascribed to them in the LOI, unless otherwise defined herein.

NOW, THEREFORE, in consideration of the mutual covenants and promises contained herein and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties agree as follows:

1. AMENDMENT TO LOI

1.1 Amendment. The LOI is hereby amended as set forth in this Section 1. All references to the "LOI" in the LOI shall be deemed to include this Addendum. The following provisions of the LOI are modified as follows:

Amended Provisions (describe affected sections and exact replacement language):

1.2 Additional Clarifications. To the extent of any conflict between the terms of the LOI and this Addendum, the terms of this Addendum shall control.

2. EFFECTIVE DATE; TERM

2.1 Effective Date. This Addendum shall become effective on the date first written above and shall be deemed retroactive to the extent expressly stated herein. The parties acknowledge and agree that certain obligations under the LOI may be deemed to have been modified effective as of .

2.2 Term. Except as expressly amended hereby, the LOI shall remain in full force and effect until terminated pursuant to its terms or by mutual written agreement of the parties.

3. CONSIDERATION

The parties acknowledge that the mutual covenants and undertakings set forth in this Addendum constitute adequate and binding consideration for the amendments set forth herein.

4. CONFIDENTIALITY

4.1 Survival of Confidentiality. The confidentiality obligations set forth in the LOI shall survive and shall apply equally to the terms of this Addendum. Each party shall continue to treat as confidential and not disclose to any third party any non-public information supplied by the other party in connection with the LOI and this Addendum except as required by law.

5. REPRESENTATIONS; AUTHORITY

Each party represents and warrants that it has full corporate power and authority to enter into and perform its obligations under this Addendum, and that the execution and delivery of this Addendum has been duly authorized by all necessary corporate or other action.

6. NOTICES

All notices under this Addendum shall be in writing and delivered in accordance with the notice provisions of the LOI or, if none, to the addresses set forth below. Notices shall be deemed given upon receipt when delivered personally, sent by nationally recognized overnight courier, or three (3) business days after deposit with the United States Postal Service, postage prepaid, certified mail, return receipt requested.

Notice Address for First Party Notice Address for Second Party

7. AMENDMENTS; WAIVER

This Addendum may be amended or modified only by a written instrument executed by authorized representatives of both parties. No waiver of any breach or default shall be effective unless in a writing signed by the party granting the waiver, and no single waiver shall constitute a waiver of any subsequent breach.

8. BINDING EFFECT; ASSIGNMENT

This Addendum shall be binding upon and inure to the benefit of the parties and their respective successors and permitted assigns. Neither party may assign its rights or delegate its obligations under this Addendum without the prior written consent of the other party, except to a successor in interest by merger or sale of substantially all assets.

9. GOVERNING LAW; VENUE

This Addendum shall be governed by and construed in accordance with the laws of the state identified below without regard to its conflict of law principles. The parties submit to the exclusive jurisdiction of the state and federal courts located in that state for any dispute arising out of or related to this Addendum.

Governing Law State

10. ENTIRE AGREEMENT; SEVERABILITY

10.1 Entire Agreement. Except as expressly modified by this Addendum, the LOI, as amended, 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.

10.2 Severability. If any provision of this Addendum is held to be invalid, illegal or unenforceable by a court of competent jurisdiction, such provision shall be enforced to the maximum extent permissible and the remaining provisions shall remain in full force and effect.

11. COUNTERPARTS; ELECTRONIC SIGNATURES

This Addendum may be executed in counterparts, each of which when executed and delivered will be an original, but all of which together will constitute one and the same instrument. Signatures delivered electronically, including by PDF or facsimile, shall be deemed original signatures for all purposes.

12. RATIFICATION

Except as expressly modified by this Addendum, the LOI is ratified and confirmed in all respects. The parties acknowledge that they have read and understand this Addendum and were represented by counsel or had the opportunity to seek counsel prior to execution.

Additional Terms or Special Instructions

First Party:

By:

Date:

Second Party:

By:

Date:

What a Legal LOI Addendum Is and When It Applies

A Legal LOI Addendum is a written amendment attached to an existing Letter of Intent (LOI) that modifies, clarifies, or extends one or more original LOI provisions without replacing the entire document. Common uses include updating material terms (price, timeline, exclusivity), correcting party names, adding contingencies, or extending negotiation deadlines. The addendum should expressly reference the original LOI, state the amended provisions, and be signed by authorized representatives of the parties to create a clear, auditable record of the change.

Why Use a Formal LOI Addendum Instead of a New LOI

An addendum preserves the original LOI history, narrows the scope of change, and reduces negotiation overhead by amending only targeted clauses. This approach aids enforceability, preserves timestamps for confidentiality and due diligence, and minimizes rework compared with drafting a full replacement LOI.

Who Typically Prepares and Signs an LOI Addendum

The addendum should be executed by persons with authority and stored alongside the original LOI for later reference.

Buyers and investors adjusting purchase terms during due diligence or pricing shifts.
Sellers or lessees clarifying deliverables, closing dates, or exclusivity periods.
Corporate legal counsel or transaction teams executing narrow corrections or extensions.

Who Can Sign and Why Authority Matters

Company Officer

An authorized officer (CEO, CFO, VP) typically signs on behalf of a corporation; their signature indicates binding corporate assent and avoids later challenges to authority.

Agent / Attorney-in-Fact

A duly authorized agent or attorney-in-fact may sign if the power of attorney is current and scope covers contract amendments; attach proof of authority to the addendum.

Step-by-Step: Preparing and Executing an LOI Addendum

Follow a concise sequence to prepare, review, and execute an addendum that remains enforceable and auditable.

01

Draft Amendment: Identify specific LOI sections to change and draft exact replacement language.
02

Internal Review: Have legal counsel or transaction lead confirm scope and risk implications.
03

Execute Signatures: Ensure authorized signers sign and date the addendum in the designated fields.
04

Attach and Store: Attach the addendum to the original LOI and retain both in the contract file.

Configuring an Online Workflow for the LOI Addendum

Set up a digital workflow that captures identity, records approvals, and preserves an immutable audit trail for the addendum.

Field	Configuration
Authentication	Email link + SMS code for signer verification
Document Format	Upload PDF/X or DOCX to preserve layout
Conditional Fields	Show clause-specific fields only when relevant
Notifications	Send copies to counsel and document repository

Sending and Completing the Addendum Online

A clear online flow reduces execution delay and preserves an auditable record of every action associated with the addendum.

Upload Document: Upload the addendum and link it to the original LOI file.
Place Fields: Add signature, date, and initial fields for each party.
Choose Authentication: Select email or stronger methods (SMS, KBA) where required.
Send to Signers: Distribute in the proper signing order and capture the audit trail.

Platform Requirements and Integration Notes

Confirm the platform meets industry compliance needs (HIPAA, 21 CFR Part 11) and integrates with your document repository for retention and retrieval.

Authentication Options: Email, SMS code, KBA where needed
Audit and Storage: Tamper-evident PDF with full audit log
Integrations: CRM/ERP and cloud storage connectors

Key Elements to Include in a Professional LOI Addendum

A well-drafted addendum is concise, references the original LOI, and clearly states the exact changes and effective date so parties and courts can interpret the amendment unambiguously.

Clear Reference

Identify the original LOI by title and date for unambiguous linkage.

Precise Language

Quote original clause and provide exact revised text to avoid disputes.

Effective Date

State when the amendment takes effect and whether retroactivity applies.

Signatory Block

Include printed name, title, and signature lines for each party.

Scope Statement

Clarify whether other LOI provisions remain in full force.

Attachment List

List exhibits, schedules, or documents incorporated by reference.

Security and Compliance Points to Verify Before eSigning

Encryption: TLS 1.2/1.3 in transit, AES-256 at rest

Audit Trail: Timestamp, IP, action history preserved

Certifications: SOC 2 Type II and ISO 27001

HIPAA Support: BAA available for protected health data

ESIGN / UETA: Compliant with federal and state e-sign laws

Accessibility: WCAG 2.0 Level AA support available

Typical Timelines and Deadlines for LOI Addenda

Track effective dates, response windows, filing obligations, and retention deadlines to avoid missed obligations or unintended extensions.

Response Window:

Specify how long the other party has to sign or object

Effective Date:

State whether effective on signature or a specific date

Negotiation Deadlines:

Update closing or exclusivity dates as needed

Filing Obligations:

Note any required regulatory or lender filings

Retention Start:

Record retention begins on execution date

Key Milestones From Drafting to Archival

Use a milestone sequence to coordinate approvals, signatures, recording, and long-term retention.

01

Draft Completion

Finalize amended language and exhibits for review

02

Legal Review

Obtain counsel sign-off on scope and risks

03

Execution

Collect signatures and notarization if required

04

Archival

Attach to the original LOI and store in repository

Common Errors to Avoid When Preparing an LOI Addendum

Failing to reference the exact original LOI creates ambiguity about which document was amended and can lead to disputes.
Using vague or conditional language (for example, 'subject to later agreement') undermines enforceability and creates litigation risk.
Omitting signatures, dates, or titles can allow a party to challenge authority or the timing of the amendment.
Storing the addendum separately without linking it to the LOI increases the chance it will be overlooked during closing or audit.

Potential Legal Risks and Financial Consequences

Contract Ambiguity: May lead to dispute or litigation costs

Authority Challenge: Unsigned or unauthorized signature risks unenforceability

Regulatory Filings: Late filings can trigger fines or lender breaches

Confidentiality Breach: Unauthorized disclosure may incur damages

Notarization Failure: Missing notary where required can void acknowledgement

Tax Implications: Changes affecting consideration may alter tax reporting

eSignature Pricing Snapshot for LOI Addendum Execution

Compare starting price and core capabilities relevant to executing and storing LOI addenda; signNow is listed first in this vendor comparison.

	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)	Yes	Yes	Yes	No
Audit Trail	Yes	Yes	Yes	Yes	Yes
HIPAA Compliant	Yes	Yes	Yes	No	No

Real-World Examples: LOI Addenda in Practice

These examples show how organizations used addenda to preserve deals, manage timing, and document negotiated changes.

Optica Ventures

Optica revised a payment schedule via addendum to accommodate investor timing

The change clarified milestones and preserved the original LOI's confidentiality provisions
The company retained the LOI and addendum in a single repository to streamline closing and audits.

Martin Properties

A property sale extended the closing date by addendum when financing delayed

The addendum updated the closing date and escrow instructions
The landlord used an eSignature workflow to collect signatures from all parties quickly while maintaining an audit trail.

Frequently Asked Questions About LOI Addenda

Answers to common questions when drafting, signing, or storing an LOI addendum, with practical guidance for typical problems.

Need help? Contact support

Are electronic signatures valid on addenda
Yes. Electronic signatures are legally enforceable under the ESIGN Act (15 U.S.C. §7001) and UETA where adopted, provided the transaction meets intent, consent, attribution, and record retention requirements.
When is notarization required
Notarization is generally not required for LOI addenda, but certain jurisdictions or lenders may demand notarized acknowledgements; verify state or contractual requirements before execution.
What if a signer lacked authority
If an individual lacked authority, the amendment may be voidable; attach board resolutions or powers of attorney to evidence authority and reduce challenge risk.
How do I correct a signed addendum
Prepare a second addendum stating the correction and have authorized signers execute it; avoid handwritten changes without full re-execution to prevent ambiguity.
Can an addendum change material terms
Yes; an addendum can modify material terms if parties consent and authorized signatories execute it, but substantial changes may require renegotiation or a replacement agreement.
How long should I retain the addendum
Retain the executed addendum with the original LOI for the active term plus applicable retention periods: at least 3 years for tax records and up to 6 years for HIPAA-related documents.

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