ESIGN vs eIDAS: What Founders Should Know About E-Signatures (2026)

An electronic signature is not invalid just because it is electronic. That does not mean every signed file is automatically enforceable. The contract still has to meet the rules that apply to the transaction, and a party may dispute who signed, what they agreed to, or whether required formalities were followed.

This guide focuses on selected U.S. and European Union rules. It is general information, not legal advice; rules differ by jurisdiction and document type.

What the U.S. ESIGN Act says

For transactions in or affecting interstate or foreign commerce, the federal ESIGN Act says a signature, contract, or record generally cannot be denied legal effect solely because it is electronic. It also says the Act does not change other legal requirements or require a party to accept electronic records or signatures. See 15 U.S.C. § 7001.

That is a rule about electronic form, not a guarantee that a particular agreement is valid. The parties must still satisfy applicable contract rules, and the signer must have authority to act for the person or company named in the agreement.

A separate ESIGN rule applies when another law requires certain information to be delivered to a consumer in writing. In that situation, § 7001(c) sets out consent and disclosure conditions for providing that information electronically. It is not a universal consent checklist for every business contract.

Some U.S. records have special rules

ESIGN lists exceptions, including wills and testamentary trusts, certain family-law matters, specified court documents and notices, and certain records involving hazardous materials. Other federal or state rules may impose additional requirements. Check the law for the specific document and transaction; do not rely on a general e-signature rule alone. See 15 U.S.C. § 7003.

What EU eIDAS says

Under Article 25 of the eIDAS Regulation, an electronic signature cannot be denied legal effect or admissibility as evidence solely because it is electronic or is not a qualified electronic signature. Article 25 gives a qualified electronic signature the equivalent legal effect of a handwritten signature. These are different protections; the regulation does not say every signature has identical evidentiary weight. See the consolidated eIDAS Regulation, Articles 25–26.

National law can still matter for the contract itself and for particular formalities. A qualified signature may be appropriate or required in some settings, but the right level depends on the transaction and applicable rules.

Legal effect and proof are separate questions

A law may recognize electronic signatures while the parties still disagree about a particular signing event. A useful record helps answer:

• Who acted? Keep the signer’s name, role, and the method used to verify access. Confirm company signers had authority where that matters.
• What did they sign? Retain the final document and a reliable way to identify its version. A file hash can help detect later changes, but it does not prove who signed.
• Did they intend to sign? Keep the steps that show the signer was presented with the document and took an affirmative signing action.
• When did it happen? Preserve timestamps and the sequence of relevant events, including delivery of the completed copy.
• Can the record be retrieved? Store the signed document and supporting log in a form that authorized parties can access and reproduce for the required retention period.

An IP address, device record, or identity check may add context, but these fields are not a universal legal requirement. Collect and retain personal data only as permitted by the privacy rules that apply to your users.

A short review before sending

Before using e-signatures for a transaction, confirm:

1. The applicable jurisdiction and document type allow the electronic process you plan to use.
2. Each signer is the intended person and has authority to sign.
3. The signing flow clearly presents the final terms and records an affirmative action.
4. Both sides can access an accurate copy after signing.
5. Any consumer disclosure, witnessing, notarization, retention, or other formal requirement is handled separately.

For a step-by-step signing workflow, see How to Sign Documents Online Legally. For a closer look at signing records, read our e-signature audit-trail guide.

The practical answer is: electronic form alone is usually not a reason to reject a signature, but the applicable law and the evidence for the specific signing event still matter.