A signature is any mark, sound, or process a person uses with the intent to authenticate a document, and understanding how signatures work comes down to two things the law looks for every time: did the signer mean to sign, and can the signature be traced to them. Federal law treats a handwritten name, a typed name at the bottom of an email, and a click on an “I Accept” button as equally valid. Format is not what makes a signature binding. Intent and attribution are.
The Two Things Every Signature Needs
Two overlapping laws set the ground rules in the United States. The Electronic Signatures in Global and National Commerce Act (E-SIGN Act), enacted in 2000, is a federal law that applies to transactions affecting interstate or foreign commerce. The Uniform Electronic Transactions Act (UETA) is a model law that 49 states, the District of Columbia, Puerto Rico, and the U.S. Virgin Islands have adopted in some form. Together, they establish that no signature or contract can be thrown out solely because it was created or delivered electronically.1Office of the Law Revision Counsel. 15 USC 7001 – General Rule of Validity
The E-SIGN Act defines an electronic signature as “an electronic sound, symbol, or process, attached to or logically associated with a contract or other record and executed or adopted by a person with the intent to sign the record.”2Office of the Law Revision Counsel. 15 USC 7006 – Definitions That phrase at the end does the real work. If you accidentally type your name into a draft you never meant to send, you haven’t signed anything. The act of signing — click, draw, scribble, type — must be the way you are saying “I agree.”
The second requirement is attribution. The signature has to be traceable to the specific person who supposedly signed. A document with a generic typed name and no evidence of who typed it has a serious attribution problem. Courts look at surrounding context: email addresses, login credentials, IP logs, handwriting analysis, witness accounts. Without both intent and attribution, a contract built on the signature can be declared unenforceable.
Formats That Count as a Signature
Because the law cares about intent rather than form, the range of actions that qualify is broader than most people expect.
- Wet ink. The traditional pen-on-paper signature. Many industries still require this for high-stakes documents like property deeds, long-term bonds, and original court filings. The physical document itself becomes the primary evidence.
- Typed name. A name typed at the end of an email or into a signature field on a form can function as a legally binding signature when the person typed it with the intent to approve the contents.
- Click-to-accept. Clicking “I Agree” on a website is a form of electronic signature. Courts have upheld these in countless disputes, provided the user had a reasonable opportunity to review the terms before clicking.
- Drawn on a touchscreen. Signing with a finger or stylus on a tablet or phone replicates the visual appearance of a handwritten signature and is treated identically under the law.
- Uploaded image. Pasting a scanned image of your handwritten signature onto a document also works, though this method raises more attribution concerns since anyone with the image file could place it.
Marks and Symbols
Someone who cannot write their name — because of illiteracy, physical disability, or any other reason — can sign using a mark such as an “X” or another symbol. This practice is centuries old and remains legally recognized. The requirements vary by jurisdiction, but the general pattern is consistent: one or two witnesses observe the person making the mark, the person’s printed name appears near the mark, and at least one witness typically signs the document as well. Some jurisdictions also require a notary to add a note explaining that the document was executed by mark. These extra steps exist because a symbol alone does not identify anyone. The witnesses provide the attribution the mark itself lacks.
When Electronic Signatures Do Not Apply
The E-SIGN Act carves out entire categories of documents where electronic signatures cannot substitute for traditional ones. This matters, because an electronically signed will or court filing could be treated as if it was never signed at all. The excluded categories include:
- Wills, codicils, and testamentary trusts, which must follow each state’s execution requirements and almost universally demand a physical signature and witnesses.
- Family law documents, including adoption papers and divorce decrees, which are governed by state rules that typically require wet-ink signatures.
- Court orders and official court documents, which follow court-specific rules rather than the E-SIGN Act.
- Certain consumer notices: cancellation of utility services, foreclosure or eviction notices, cancellation of health or life insurance benefits, and product recall notices, all of which require paper delivery.
- Hazardous materials shipping papers and handling instructions, which must be in physical form.
- Most Uniform Commercial Code transactions. The E-SIGN Act does not apply to UCC-governed contracts except for the sale of goods (Article 2) and leases (Article 2A), which can use electronic signatures.
These exclusions live in 15 U.S.C. § 7003.3Office of the Law Revision Counsel. 15 USC 7003 – Specific Exceptions State laws may add their own exclusions on top of the federal list, so a document type that is allowed electronically in one state could still require a physical signature in another.
Consumer Consent for Electronic Records
When a law requires a business to deliver information to a consumer in writing — loan disclosures, insurance terms, billing statements — the business can switch to electronic records only if the consumer affirmatively opts in. Before obtaining consent, the business must tell the consumer about their right to receive paper copies, explain how to withdraw consent later, disclose any fees or consequences of withdrawal, and list the hardware and software needed to access the electronic records. The consumer must then demonstrate they can actually open the electronic format, usually by completing the consent process online.4Office of the Law Revision Counsel. 15 USC Ch. 96 – Electronic Signatures in Global and National Commerce A business that skips these steps or buries the disclosure may find that its electronic delivery does not satisfy the underlying legal requirement, even though the consumer technically agreed.
What an E-Signature Platform Actually Captures
When you sign a document through a platform like DocuSign, HelloSign, or Adobe Sign, the software does far more than record your name. It builds an audit trail — a chronological record of everything that happened during the signing process. That trail typically includes the signer’s email address, IP address, the exact timestamps for when the document was sent, opened, and signed, and whether the signer’s identity was verified through email confirmation or another method.
That audit trail is what gives electronic signatures their courtroom staying power. If someone later claims they never signed, the platform can produce a log showing that a document was sent to their email, opened from their IP address at a specific time, and signed with their credentials. Forgery claims become much harder to sustain against that level of documentation. The audit log also detects post-signature tampering: if anyone alters the document after execution, the platform flags it as modified.
Federal law requires that the data constituting an electronic signature be stored in a way that permanently associates it with the signed record, and that the record itself be locked against modification after signing. Businesses should retain these records for as long as the underlying transaction could give rise to a legal dispute, which depending on the contract type and applicable statute of limitations could mean several years or longer.
How Digital Signatures Differ
A digital signature is a specific type of electronic signature that uses cryptographic technology to verify both the signer’s identity and the document’s integrity. Where a standard electronic signature might be as simple as a typed name, a digital signature involves mathematical algorithms that make tampering detectable.
The process works through a pair of linked keys. The signer holds a private key that only they control and uses it to encrypt a mathematical summary — called a hash — of the document’s contents. Anyone receiving the document can use the signer’s public key, which is freely available, to decrypt that hash and compare it against their own calculation of the document’s contents. If the two match, two things are confirmed: the document has not been altered since signing, and only the holder of the private key could have signed it.
This system relies on Public Key Infrastructure (PKI), a framework of trusted Certificate Authorities that issue digital certificates. A certificate is essentially a verified digital ID card that links a public key to a specific person or organization. When you receive a digitally signed document, your software checks the certificate against the issuing authority to confirm the signer’s identity. If any part of the document has changed, even a single character, the cryptographic hash will not match and verification fails. This level of security makes digital signatures the standard for high-value financial transactions, government filings, and cross-border agreements.
Who Has the Legal Power to Sign
A signature is only as binding as the legal capacity of the person who made it. Capacity means two things: the signer has reached the age of majority (18 in most jurisdictions) and is mentally capable of understanding what they are agreeing to. A signature obtained from someone who was intoxicated, under duress, or suffering from a cognitive impairment that prevented comprehension is not automatically void. It is voidable, meaning the impaired party can later choose to challenge it. Courts look at whether the person understood the nature and consequences of the document at the moment they signed.
Signing for a Company
In business transactions, the question shifts from “can this person sign” to “does this person have the right to bind this organization.” A company’s bylaws or operating agreement typically designate which officers or members can execute contracts. An employee who signs a major vendor agreement without proper authorization has not necessarily created a binding deal. The company may be able to disavow the contract if the other party knew or should have known the employee lacked authority.
For large transactions, the other side often requests an incumbency certificate, a document signed by the company’s secretary that lists the names, titles, and specimen signatures of everyone authorized to sign on the company’s behalf. If the secretary’s own authority needs verification, another officer countersigns the certificate. This layered verification exists because companies change personnel frequently, and a signature from last quarter’s VP of Operations may carry no authority today.
Signing Under a Power of Attorney
An individual can authorize someone else to sign on their behalf through a power of attorney (POA). The agent signing under a POA must typically indicate the arrangement in the signature itself, for example “Jane Smith, by John Doe under POA,” so that anyone reviewing the document knows the signer was acting as a representative rather than a principal party. The POA document must specifically grant the agent authority over the type of transaction involved. A POA covering financial matters will not authorize the agent to sign medical directives, and a POA that has been revoked or expired carries no authority at all.
Witnesses and Notaries
Some documents require more than a signature. They need independent verification that the signing actually happened the way it was supposed to. Witnessing and notarization serve different functions, and confusing them or skipping the wrong one can invalidate an otherwise perfectly good document.
What a Witness Does
A witness is someone who physically observes the signing act and then adds their own signature to confirm what they saw. The witness is not vouching for the contents of the document. They are confirming that the named person actually signed it, appeared to be acting voluntarily, and seemed to understand what they were doing. Wills are the most common documents requiring witnesses, and most states demand two. A will signed without the required witnesses may be entirely unenforceable in probate, regardless of how clearly it reflects the deceased person’s wishes.
What a Notary Does
A notary public is a state-authorized official who verifies identities and confirms that signers are acting voluntarily. The notary checks government-issued identification, confirms the signer understands the document’s nature, and affixes an official seal or stamp. Notarization does not mean the notary reviewed or approved the document’s contents. It means the notary confirmed the identity and willingness of the signer.
Notarization is mandatory for certain documents to have legal effect. Property deeds and mortgages generally must be notarized before a county recorder will accept them for filing. Statutory maximum fees for notary services range from $2 to $25 per signature depending on the state, and about a dozen states do not set a statutory cap at all. Remote notarizations, where the signer appears by video rather than in person, often carry higher fees under separate state rules.
Remote Online Notarization
As of 2025, over 40 states and the District of Columbia have enacted permanent laws allowing remote online notarization (RON), where the signer and notary connect through a live audio-video session rather than meeting face to face. RON platforms use a multi-step identity verification process: the signer presents a government-issued ID on camera, automated software analyzes the credential’s layout and security features, and the signer answers knowledge-based authentication questions drawn from public and private data sources. The session is recorded and retained as part of the transaction record. Whether a remotely notarized document is accepted still depends on the laws of both the state where the notary is commissioned and the state where the document will be used.
What Happens When a Signature Is Forged
Forging someone’s signature on a check, deed, contract, or government form carries both criminal penalties and civil liability. The severity depends on what was forged and which jurisdiction prosecutes.
Federal Penalties
Federal forgery statutes primarily target documents that involve the U.S. government. Forging a government obligation or security such as a Treasury bond carries up to 20 years in prison. Forging a deed, contract, power of attorney, or receipt to obtain money from the federal government carries up to 10 years. Forging a government contractor’s bond or public record also carries up to 10 years.5Office of the Law Revision Counsel. 18 USC Ch. 25 – Counterfeiting and Forgery Separately, using a forged signature as part of an identity fraud scheme can carry up to 15 years under federal identity document statutes.
State Penalties
Most forgery prosecutions happen at the state level, where the offense is typically a felony. Prison sentences for a standard forgery conviction generally range from one to seven years, though the exact penalty depends on the state and the type of document forged. Many states grade forgery into degrees based on what was forged. Forging a stock certificate or government-issued document tends to be treated more seriously than forging a personal check, and a first-degree conviction can carry significantly longer sentences.
Civil Liability
Beyond criminal prosecution, the person whose signature was forged can pursue civil remedies. The most common are a lawsuit for financial damages caused by the forgery and a court order voiding the forged contract entirely. A forged deed does not actually transfer property, and the true owner can sue to have the fraudulent deed set aside and recover any losses. When a signature is challenged in court, the person alleging forgery generally bears the initial burden of proving the signature is not genuine, particularly when the document in question was formally recorded or notarized. Registered documents carry a presumption of authenticity that the challenger must overcome.