Authority to sign

What a signature attests to

Last checked 6 November 2026 · 10 sources

Short answer

A signature does not always mean the same thing. Singapore's Electronic Transactions Act defines it as a method used to identify a person and to indicate that person's intention ¹. What the person intends depends on the document. A treaty signature subject to ratification only authenticates the text ². A Sarbanes-Oxley certification states that the officer reviewed a report and that it fairly presents the company's finances ³. An apostille certifies the signature and capacity of the person who signed a public document ⁴.

Identify and show intention: Singapore Electronic Transactions Act 2010 definition of signature ¹
Authenticate a text: Treaty signature subject to ratification ²
Certify accuracy: CEO and CFO certification under 15 U.S.C. 7241 ³
Certify another signature: Apostille under the 1961 Hague Convention ⁴
Handwritten equivalence in the EU: Qualified electronic signature, eIDAS Article 25 ⁵

Identity and intention

Most legal definitions focus on two things. Singapore's Electronic Transactions Act 2010 says a signature is a method, electronic or otherwise, used to identify a person and to indicate the intention of that person ¹. The UK Electronic Communications Act 2000 defines an electronic signature as material linked to a communication that purports to be used by the individual creating it to sign ⁶.

A mark can be enough. Section 1 of the UK Law of Property (Miscellaneous Provisions) Act 1989 says signing includes making one's mark ⁷.

Five things a signature can attest to

The same act of signing can carry very different meanings. The list below gives examples from official texts.

Agreement to be bound. A treaty definitive signature establishes a state's consent to be bound where the treaty is not subject to ratification ².
Authentication only. A signature subject to ratification is a means of authentication and shows willingness to continue the treaty process ².
Certification of accuracy. A Sarbanes-Oxley section 302 certificate states that the officer reviewed the report and that, to the officer's knowledge, it contains no untrue statement of a material fact ³.
Certification of another signature. An apostille certifies the authenticity of the signature on a public document, the capacity in which the signer acted and the identity of any seal or stamp ⁴.
Formal completion of a decision. A US bill passed by both Houses goes to the President, who signs it if he approves ⁸.

Who the signer acts for

A signer often acts in a capacity, not personally. Under the UK Companies Act 2006, a document signed by two authorised signatories, or by a director before a witness, and expressed to be executed by the company, has the same effect as if executed under the company's common seal ⁹. The apostille register records the name and capacity of the person who signed the underlying document ⁴.

Electronic signatures and evidential weight

Electronic signature laws separate legal effect from evidential weight. Under the EU eIDAS Regulation, an electronic signature shall not be denied legal effect or admissibility as evidence solely on the grounds that it is electronic. Only a qualified electronic signature has the equivalent legal effect of a handwritten signature ⁵. In the US, a signature or contract relating to interstate or foreign commerce may not be denied legal effect solely on the grounds that it is in electronic form ¹⁰.

Document	What the signature attests to
Treaty, definitive signature ²	Consent of the state to be bound ²
Treaty, subject to ratification ²	Authentication of the text ²
SOX section 302 certificate ³	Review, accuracy, fair presentation and internal controls ³
Apostille ⁴	Genuineness of the underlying signature, capacity and seal ⁴
UK company deed ⁹	Execution by the company ⁹

Common questions

Does signing a document always mean agreeing to it?

No. A treaty signature subject to ratification only authenticates the text, and consent to be bound comes later ².

What does a signature legally need to show?

Singapore's law defines a signature as a method used to identify a person and indicate that person's intention ¹.

Does an apostille check the content of a document?

The 1961 Convention says it certifies the signature, the capacity of the signer and any seal or stamp ⁴. It does not say it certifies content.

Is an electronic signature as good as a handwritten one in the EU?

Under eIDAS, a qualified electronic signature has the equivalent legal effect of a handwritten signature ⁵.

Rules and charges change. Check the official source linked on this page before you pay or travel. Spotted an error? Email hello@whosignedwhat.com.

Sources

Signatory, witness and decision-maker explained
The difference between the person who signs a document, the witness who attests the signature and the body that made the decision, with sourced examples.
Company signing authority compared
Who may sign documents for a company under the UK Companies Act 2006 sections 43 and 44 and Delaware corporate law, and what a buyer may assume.
Sarbanes-Oxley sections 302 and 906 certifications explained
What a CEO and CFO sign under Sarbanes-Oxley sections 302 and 906, what each statement covers, the penalties, and similar rules in Canada and the EU.
Treaty signature versus ratification
Why signing a treaty usually does not bind a state, what ratification, acceptance and accession do, and how the Vienna Convention sets the rules.
Electronic signature laws compared
How the EU eIDAS Regulation, the US ESIGN Act and laws in the UK, Canada, India and Singapore treat electronic signatures and their tiers.
Notarisation and the apostille explained
What an apostille certifies under the 1961 Hague Convention, how it differs from legalisation and notarisation, and how the UK and US issue them.