Authority to sign

Signatory, witness and decision-maker explained

Last checked 6 November 2026 · 6 sources

Short answer

The three roles are often confused. A signatory signs the document. A witness attests that the signature was made in their presence, as UK deed rules require ¹. A decision-maker is the body whose decision the document records, such as a legislature or a board. A treaty signatory with full powers authenticates the text, but the state's consent to be bound comes later by ratification ². In Germany a minister countersigns presidential acts before they are valid ³.

UK deed by an individual: Signed in the presence of one attesting witness, or at the signer's direction before two witnesses ¹
UK company by one director: Director signs in the presence of an attesting witness ⁴
Treaty signature: Authentication, consent to be bound comes by ratification ²
Germany countersignature: Federal Chancellor or competent Federal Minister, Article 58 Basic Law ³
Canada written assent: More than one member of each House may witness it ⁵

Three roles, three kinds of responsibility

The signatory is the person whose signature appears on the document. In company law the signatory often signs on behalf of someone else. Under section 44 of the UK Companies Act 2006, a person signing for more than one company must sign separately in each capacity ⁴.

The witness attests that the signature was made. Under the Law of Property (Miscellaneous Provisions) Act 1989, the witness attests the signature of the person executing the deed ¹.

The decision-maker is the body that decided. A US bill is decided by both Houses of Congress before it is presented to the President for signature ⁶. A treaty is decided by the organ that ratifies it, not by the diplomat who signed ².

Witness rules for deeds

Section 1(3) of the 1989 Act gives two ways for an individual to execute a deed ¹.

Sign it in the presence of a witness who attests the signature ¹.
Have it signed at the individual's direction, in that person's presence and the presence of two witnesses who each attest the signature ¹.
In both cases the deed must be delivered as a deed ¹.
Making a mark counts as signing ¹.

Signing for an organisation

A UK company can sign a document through two authorised signatories, or through one director signing in the presence of a witness who attests the signature ⁴. Authorised signatories are every director and, in some companies, the secretary ⁴. The witness here confirms the director's signature. The board's authority is a separate question, which the page on company signing authority covers.

International law draws the same line. Full powers are a document from a state's competent authority designating a person to negotiate, adopt or authenticate a treaty, or to express consent to be bound ². Heads of State, Heads of Government and Foreign Ministers do not need to present them ².

Countersignature and ministerial responsibility

Some constitutions require a second signature. Article 58 of the German Basic Law says orders and directions of the Federal President require for their validity the countersignature of the Federal Chancellor or of the competent Federal Minister, with listed exceptions ³. Article 82 says federal laws are certified by the Federal President after countersignature ³.

Canada's Royal Assent Act lets assent be given by written declaration. More than one member of each House may witness that declaration ⁵. Here the witnesses are parliamentarians, and the decision has already been taken by both Houses ⁵.

Document	Signatory	Witness or countersigner	Decision-maker
UK deed by an individual ¹	The individual, or a person at their direction ¹	One or two attesting witnesses ¹	The individual ¹
US federal bill ⁶	The President ⁶	None in the Constitution ⁶	Both Houses of Congress ⁶
Treaty subject to ratification ²	Representative with full powers ²	None	Organ that ratifies ²

Common questions

What does a witness to a signature confirm?

Under UK deed rules, the witness attests the signature of the person executing the deed ¹.

How many witnesses does a UK deed need?

One, if the individual signs personally. Two, if someone signs at the individual's direction ¹.

Is the person who signs a treaty the one who decides?

No. A signature subject to ratification authenticates the text. Consent to be bound comes through ratification ².

What is a countersignature?

A second signature by a minister. In Germany, orders and directions of the Federal President need the countersignature of the Chancellor or competent minister to be valid ³.

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

What a signature attests to
A signature can mean agreement, authentication, certification of accuracy or a decision. How laws in the US, EU, UK and at the UN define each meaning.
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.
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.
Assent and enactment of legislation compared
Who signs a bill into law in the US, UK, Canada and Germany, what that signature attests to, and what happens if the head of state does not sign.