What is an Electronic Signature?

An electronic signature is any electronic sound, symbol, or process attached to or logically associated with a contract or record and executed or adopted by a person with the intent to sign. Under US federal law, this definition — set out in the Electronic Signatures in Global and National Commerce Act — grants electronic signatures the same legal weight as a handwritten signature for most commercial and consumer transactions.¹

The key phrase is intent to sign. A typed name at the bottom of an email, a scanned handwritten signature, a PIN entered on a tablet, or a click on an ‘I agree’ button can each constitute a valid electronic signature if the signer adopted it with that intent. The technology used matters far less than whether the signer intended to be legally bound.

Types of Electronic Signatures

Not all electronic signatures carry the same evidential weight. The eIDAS Regulation in the European Union distinguishes three tiers, each balancing convenience against security:

• Simple Electronic Signature (SES) — the broadest category. A typed name, a checkbox, or a scanned signature image. Widely accepted for routine business documents but offers limited forensic value if the signature is disputed in court.
• Advanced Electronic Signature (AES) — uniquely linked to the signatory, capable of identifying them, and tied to the signed data in a way that detects subsequent tampering. Typically implemented via certificate-based signing or email/SMS one-time-passcode authentication with a timestamped audit trail.
• Qualified Electronic Signature (QES) — the highest tier under eIDAS. Created using a qualified signature creation device and backed by a qualified certificate issued by a regulated trust service provider. Legally equivalent to a handwritten signature across all EU member states as a matter of statute, with no room for challenge on the basis of form alone.

Legal Framework in the United States

Two complementary statutes govern electronic signatures across US jurisdictions. The ESIGN Act (2000) establishes baseline validity for electronic signatures in interstate and foreign commerce.¹ The Uniform Electronic Transactions Act (UETA), adopted by 49 states and the District of Columbia, governs intrastate transactions on the same principles.²

Both statutes share four core principles: (1) an electronic signature cannot be denied legal effect solely because it is in electronic form; (2) parties must consent to conducting the transaction electronically; (3) records must be capable of retention and accurate later reproduction; and (4) the signature must be attributable to the person whose signature it purports to be.

When Electronic Signatures Are Not Legally Valid

The ESIGN Act carves out several document types that cannot be executed electronically regardless of the parties’ consent:

• Wills, codicils, and testamentary trusts
• Adoption papers and divorce proceedings
• Court orders and official court documents
• Notices of utility disconnection, eviction, or repossession
• Product safety recall notices

State law may impose additional restrictions, particularly in real estate where deeds and mortgages often require notarisation. Always verify jurisdiction-specific requirements before relying on an electronic signature for high-stakes or irreversible transactions.

Best Practices for Electronic Signature Compliance

Adopting electronic signatures without a clear compliance framework creates evidentiary risk if a signature is ever challenged. The following practices reduce that risk materially:

• Capture and retain a complete audit trail — timestamps, IP addresses, email verification codes, and signing sequence records all strengthen the attribution of a signature to a specific individual.
• Obtain clear, affirmative consent — both ESIGN and UETA require the counterparty to affirmatively agree to conduct the transaction electronically. Pre-ticked consent boxes are legally questionable in several jurisdictions.
• Match signature strength to document risk — a typed name is appropriate for a routine service agreement; a qualified electronic signature backed by identity verification is more appropriate for high-value contracts, regulated financial products, or cross-border transactions.
• Use tamper-evident storage — the signed document and its accompanying audit trail should be stored in a format that can demonstrate the record has not been altered since the moment of execution.