An electronic signature is any digital indication that a person intends to agree to the contents of a document. E-signatures are legally recognised in most countries and have the same legal effect as a handwritten signature for the vast majority of commercial agreements.
What is an electronic signature?
An electronic signature — commonly called an e-signature — is a broad term for any electronic process that expresses a person's agreement to or acceptance of a document. The simplest examples include typing your name into a signature field, clicking an “I agree” checkbox, or drawing your name on a touchscreen. More sophisticated forms involve cryptographic certificates that mathematically bind the signature to the specific document being signed.
The defining characteristic of an e-signature is intent. Courts and regulators worldwide look at whether the person who signed understood what they were agreeing to and deliberately took an action to signify that agreement. The technology used to capture the signature matters far less than the intent behind it.
E-signatures are used in virtually every industry — from employment contracts and lease agreements to sales orders and non-disclosure agreements. Any document that once required a wet ink signature can, in most cases, be executed electronically with equal legal force.
How does an electronic signature work?
The workflow for electronically signing a document typically follows four steps:
- Document preparation. The sender uploads a PDF or other document and places signature fields, date fields, and any other input fields on the pages that require them.
- Invitation to sign. The platform sends the signer a unique, secure link via email. No account or special software is needed to follow the link.
- Signing.The signer opens the document in their browser, reviews it, and completes each field — drawing, typing, or clicking to apply their signature. The platform records metadata at the moment of signing (see “What an e-signature captures as evidence” below).
- Completion. Once all required parties have signed, the platform generates a finalised document. A certificate of completion, containing the full audit trail, is typically appended to or distributed alongside the signed document.
Throughout this process the platform creates a cryptographic hash of the document. If any byte of the document changes after signing, the hash will no longer match, making tampering immediately detectable. This integrity mechanism is what gives e-signed documents their evidential weight.
Types of electronic signatures
Not all e-signatures are created equal. Legal frameworks, especially the EU's eIDAS Regulation, define a tiered hierarchy based on security level and the assurance of the signer's identity.
Simple Electronic Signature (SES)
A Simple Electronic Signature is any electronic data that is used as a signature. Typing your name at the bottom of an email, checking a tick-box on a web form, or clicking “Accept” on a terms-of-service page are all simple e-signatures. SES offers the lowest level of assurance because it does not verify identity independently, but it is legally valid for a very wide range of everyday agreements.
Advanced Electronic Signature (AES)
An Advanced Electronic Signature must be uniquely linked to the signatory, capable of identifying the signatory, created using data under the signatory's sole control, and linked to the signed data in such a way that any subsequent change is detectable. In practice this is achieved through asymmetric cryptography: the platform generates a key pair and uses the private key — accessible only to the signer — to sign a hash of the document. AES is appropriate for higher-value commercial contracts where a stronger chain of identity is desirable.
Qualified Electronic Signature (QES)
A Qualified Electronic Signature is an Advanced Electronic Signature created using a Qualified Electronic Signature Creation Device (QSCD) and backed by a qualified certificate issued by a trust service provider that appears on an official EU trusted list (or equivalent national registry). QES carries the highest legal weight — under eIDAS it has the equivalent legal effect of a handwritten signature across all EU member states. QES is most commonly required for notarial acts, regulated financial instruments, and government transactions.
For the overwhelming majority of business agreements — NDAs, service contracts, employment offers, lease agreements, purchase orders — a Simple or Advanced Electronic Signature is entirely sufficient.
Are electronic signatures legally valid?
Yes, in most jurisdictions. Two landmark frameworks set the international standard:
- ESIGN Act (United States, 2000). The Electronic Signatures in Global and National Commerce Act established that electronic signatures and records have the same legal standing as their paper equivalents for interstate and foreign commerce. Neither federal nor state law may deny validity to a contract solely because it was executed electronically.
- eIDAS Regulation (European Union, 2014). eIDAS (Electronic Identification, Authentication and Trust Services) created a harmonised framework across all EU member states. It introduced the three-tier signature hierarchy (SES / AES / QES) and mandated that no e-signature may be denied legal effect solely because it is in electronic form.
Beyond the US and EU, countries including the United Kingdom (Electronic Communications Act 2000, updated post-Brexit), Canada (PIPEDA and provincial UETA equivalents), Australia (Electronic Transactions Act 1999), India (Information Technology Act 2000), Singapore (Electronic Transactions Act), and many others have enacted substantially similar legislation. The global default is that e-signatures are valid.
There are exceptions. Documents that most jurisdictions continue to require in wet-ink form include wills and codicils, certain property conveyances, court orders, and negotiable instruments in some classifications. Always check local requirements for high-stakes transactions where doubt exists. For a deeper look at legal validity, see our article on are electronic signatures legally binding.
What an e-signature captures as evidence
A reputable e-signature platform does more than record a drawn or typed name. It assembles a forensic evidence package at the moment of signing that can be used to authenticate the transaction if it is ever disputed. The key data points captured include:
- Full name of the signer as entered during the signing process.
- IP addressfrom which the document was signed, placing the signer's device on a network at a specific location and time.
- Timestamp(UTC) of every action — when the link was opened, when each field was completed, when the final signature was applied.
- Device and browser fingerprint— operating system, browser version, and screen resolution — corroborating the identity evidence.
- Document hash (SHA-256 or equivalent) computed at the moment of signing. If the document is altered even by a single character afterwards, the hash will not match and tampering becomes immediately provable.
- Email addressto which the signing invitation was sent, linking the signer's identity to the action.
This audit trail is typically compiled into a certificate of completion that accompanies the signed document. Courts treat this package as strong circumstantial evidence of authenticity — often far stronger than a wet ink signature, which captures nothing beyond the mark itself.
Electronic signature vs handwritten signature
People sometimes assume that a handwritten signature is inherently more secure or more legally robust than an electronic one. In practice, the opposite is often true.
| Attribute | Handwritten signature | Electronic signature |
|---|---|---|
| Identity verification | None at point of signing — relies on witness or notary | Email, IP, device data captured automatically |
| Tamper evidence | Document can be altered after signing without detection | Document hash detects any post-signing change |
| Audit trail | None — only the mark exists | Full timestamped log of every action |
| Speed | Requires printing, signing, scanning, emailing | Minutes from any device |
| Storage & retrieval | Physical filing; can be lost or damaged | Cloud-stored, searchable, permanent |
| Legal standing | Recognised everywhere | Recognised in most jurisdictions for most documents |
The handwritten signature's only remaining advantage is universal recognition — there is no jurisdiction that rejects it. But for the vast majority of commercial agreements, the electronic signature's evidence trail makes it the more defensible option.
If you're interested in the technical distinction between an e-signature and a digital signature (a specific cryptographic mechanism), see our explainer on electronic signature vs digital signature.
Frequently asked questions
Is an e-signature the same as a digital signature?
No — though the terms are often used interchangeably in everyday speech. An electronic signature is any electronic indication of intent to agree; it is a legal concept. A digital signature is a specific cryptographic technique that uses a key pair to bind the signer's identity to a document mathematically. All digital signatures are e-signatures, but not all e-signatures are digital signatures. A typed name in a signature box is an e-signature but not a digital signature.
Can any document be signed electronically?
Most documents can be signed electronically, but there are exceptions. Wills, certain property deeds, court-filed instruments, and some regulated financial documents may still require wet ink signatures in certain jurisdictions. When in doubt, consult a legal professional for the specific document type and jurisdiction. For the vast majority of business contracts — NDAs, service agreements, employment offers, rental agreements, purchase orders — an e-signature is fully valid.
Does the signer need special software or an account?
No. With modern e-signature platforms, signers receive an email containing a secure link. They click the link, review the document in their web browser, complete the required fields, and apply their signature — all without downloading software or creating an account. This makes e-signing accessible from any device, including smartphones, and removes friction for the recipient.
What happens if someone disputes an electronically signed document?
The audit trail captured at signing — IP address, timestamp, device fingerprint, email address, and document hash — forms the evidentiary basis for resolving disputes. The certificate of completion generated by the platform can be submitted as evidence demonstrating that a specific person, at a specific time, from a specific device, signed a document whose contents have not changed since. Courts in the US, EU, and most other jurisdictions have routinely upheld electronically signed documents on the basis of this evidence.
How is an e-signature different from just typing a name at the bottom of an email?
Both are technically forms of electronic signature, but they differ significantly in evidential strength. Typing a name at the bottom of an email lacks a document hash (the email body can be altered), has no formal audit log, and does not clearly separate the signature from conversational text. A purpose-built e-signature platform records the exact state of the document at signing, locks it with a cryptographic hash, and generates a timestamped audit certificate — making the transaction far easier to defend if challenged. For anything more consequential than an informal acknowledgment, a dedicated e-signature workflow is strongly preferable.