Ad Refendrum Signature
Procedure Treaty Law Preferred
Treaty signature given subject to the State's later confirmation, becoming a full signature once confirmed.
Independent referenceNot an official or legal definition
Sources citedSee the sources at the end of this page
Status Under reviewLast updated 11 October 2026
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Definition
In plain language
A diplomat signs a treaty text but the signature is only provisional until the home government confirms it. Once confirmed, it counts as a full signature.
Academic definition
Article 12(2)(b) of the Vienna Convention on the Law of Treaties provides that a signature ad referendum, if confirmed by the representative's State, constitutes a full signature of the treaty. The device lets negotiators finalise a text when their instructions are incomplete, without binding the State until the capital approves. It differs from signature subject to ratification, which expresses consent to the text but not to be bound; ad referendum signature is about whether the signature itself is valid.
Classification
- Term type
- Procedure
- Category
- Treaty Law
- Subject field
- Treaty Law
- Subfield
- Signature and Consent
- Difficulty level
- Advanced
- Grammatical category
- Latin adverbial phrase
Language variants
- Alternative terms
- Ad Referendum Signature
- signature ad referendum
- Non-preferred terms
- Ad Refendrum Signature
- Abbreviations
- not_applicable
- Acronyms
- not_applicable
- Native terms
- ad referendum (Latin, 'subject to reference')
- Transliteration
- not_applicable
- Pronunciation
- not_applicable
Context
Legal effect: Procedural
Scope
Covers a provisionally effective signature that needs confirmation; signature subject to ratification, initialling and full signature are separate steps. The listed spelling 'Refendrum' is a typographical variant of 'referendum'.
Legal context
VCLT Article 12(2)(b) governs the effect of confirmation; Article 12(2)(a) separately treats initialling as signature when negotiating States so agree. Under Article 7 a representative needs full powers or must be considered as representing the State, and ad referendum signature does not remove that requirement.
Diplomatic context
It is used when a delegation has reached an agreed text but must obtain approval from its government, often with a statement that the signature is 'ad referendum' written next to the name.
Institutional context
Handled by foreign ministries, treaty sections and the depositary, which records the signature and any later confirmation.
Historical context
The practice has long been used in diplomacy where slow communications forced envoys to sign subject to their sovereign's approval, and was codified in 1969.
Why it matters
It prevents a State from being bound by a signature its government has not endorsed while still allowing the text to be closed at the negotiating table.
Usage
Register: Legal
Usage note
The standard Latin spelling is 'ad referendum'; the glossary title contains a typographical error that editors should correct in the post title and slug.
Example
The delegate signed the agreement ad referendum, pending approval from her foreign ministry.
Example scenario
State A's negotiator signs the final text while her instructions are still being confirmed in the capital. A week later the foreign ministry informs the depositary that it confirms the signature, which then counts as a full signature under the treaty.
Common misuse
Treating ad referendum signature as the same as signature subject to ratification; the former needs confirmation of the signature itself, the latter later consent to be bound.
Not to be confused with
- Signature subject to ratification
- Initialling of a treaty text
- Full powers
Sources
- Vienna Convention on the Law of Treaties (1969), United Nations, Article 12(2)(b). legal.un.org
- Official definition. not_found_in_source
- Treaty reference. legal.un.org
- Aust, Modern Treaty Law and Practice. not_found_in_source
- not_found_in_source. not_found_in_source
Source type: Treaty. Source reliability: Primary.
This entry is an independent reference definition, not an official or legally binding text. Where an official definition exists, it is linked above and is authoritative. Read our methodology.
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