Frequently Asked Questions: Researching Treaties

This guide aims to answer questions frequently asked of the staff at the Inner Temple Library. The sources suggested are not intended to be exhaustive. Rather they are sources that the staff have found to be most useful. The sources include free web-based sources and hard copy materials. Details of the coverage of the websites can be found at the end of the guide. Works held by the Inns of Court Libraries are available for consultation to members only.

The FAQs are also available as a PDF (Adobe Acrobat Reader required).

What is the definition of a treaty?
What do the terms bilateral and multilateral mean?
What are conventions, protocols and exchanges of notes?
What is an MOU?
What is an explanatory memorandum?
Where can I find a glossary of terms used in treaty research?
How are treaties cited?
What are the different stages in treaty making?
What does it mean to “accede” to a treaty?
What does a depositary do?
How can I find out who is the depositary for a treaty?
What are “travaux preparatoires” and where can I find them?
How are UK treaties published?
Where will I find the text of UK treaties?
Where will I find the text of treaties to which the UK is not a party?
Where will I find national collections of treaties?
How can I find EU treaties?
How can I check the status and the parties to a treaty?
What is the procedure for treaties that involve UK dependencies and overseas territories?
What are the contact details for the Foreign & Commonwealth Office (FCO)?

Database Coverage

What are the coverage dates for the websites?

What is the definition of a treaty?

 “A written agreement by which two or more states or international organisations create or intend to create a relation between themselves operating within the sphere of international law” (Lord McNair, Law of Treaties, 1961).

What do the terms bilateral and multilateral mean?

  • Bilateral – between two states
  • Multilateral – between several states
  • It is important to know whether a treaty is bilateral or multilateral as the finding tools may only look at one type of treaty or may deal with the two types differently.

Back to top.

What are conventions, protocols and exchanges of notes?

  • Convention – implies a multilateral treaty e.g. European Convention on Human Rights.
  • Protocol – usually indicates a treaty which amends or supplements an earlier principal treaty e.g. the protocols amending/supplementing the European Convention on Human Rights since it was made in 1950.
  • Exchange of notes – usually a bilateral agreement on a subject of no great general importance.

What is an MOU?

  • A Memorandum of Understanding (MOU) is an informal record of a non-legally binding arrangement between states on matters that are considered unsuitable for inclusion in treaties. The terminology used in MOUs is different from the terminology used in treaties.
  • The UK does not publish MOUs and does not register them at the UN. In addition they may not be deposited at the National Archive until many years later.
  • The FCO (Foreign & Commonwealth Office) does not automatically make MOU material available but it is worth contacting the FCO to find out what is available. The FCO’s contact details are as follows: email: treatypublicenquiries@fco.gov.uk.
  • Modern Treaty Law and Practice (4th edition 2023) by Aust – has a table of MOUs. This is held by all the Inns of Court Libraries.

What is an explanatory memorandum?

  • Since 1997 any treaty laid before the UK Parliament has to be accompanied by an explanatory memorandum (EM). The aim of an EM is to provide information about the treaty.
  • EMs to 2012 are available on the FCO archived website.
  • UK Treaties within GOV.UK has Ems from 2013 onwards.

Back to top.

Where can I find a glossary of terms used in treaty research?

 Free web sources

Hard copy sources

  • Modern Treaty Law and Practice (4th edition 2023) by Aust – held by all the Inns of Court Libraries.

How are treaties cited?

 Main elements – title, date of signature, and (for multilateral treaties) place of signature.

  • Title – every treaty has a formal title, but an abbreviated form may be commonly used e.g. European Convention on Human Rights – the original formal title was Convention for the Protection of Human Rights and Fundamental Freedoms.
  • Date of signature – usually essential to know for tracing purposes.
  • Place of signature – not always essential, but often used in popular titles, e.g. the Warsaw Convention, the Treaty of Rome, and the Schengen Agreement.
  • The component sections of a treaty are usually called articles. These may be divided further into paragraphs and sub-paragraphs.

Back to top.

What are the different stages in treaty making?

  • Signing – there will be negotiations which result in an agreed text. The parties to the treaty sign but it is not yet legally binding. In the UK treaties that require ratification are laid before Parliament under the Ponsonby rule 21 days before ratification. The date of signature is important as some of the finding aids are arranged chronologically by date of signature. Occasionally the treaty will state that it will come into force on signature.
  • Ratification – follows signature and signifies the consent of a State to be bound by the treaty. It consists of the deposit of an instrument of ratification with the other state (if bilateral), or the depositary (if multilateral).
  • In force – the date the treaty comes into force will be stated in the treaty itself. However, often the date is an indeterminate one which depends on subsequent events e.g. the UN Convention on the Law of the Sea 1982, states that it will come into force after the 60th country has ratified it.

What does it mean to “accede” to a treaty?

  • Accession is the act whereby a state becomes party to a treaty that is already in force; accession has the same effect as ratification.

What does a depositary do?

  • The depositary is designated in the terms of the multilateral treaty. It performs various functions with regard to the treaty. These include: receiving signatures and instruments of ratification; communicating comprehensive and up-to-date information on the status of the treaty.

Back to top.

How can I find out who is the depositary for a treaty?

For multilateral treaties, the depositary is stated in the terms of the treaty.

Hard copy sources

  • Multilateral Treaties: Index and Current Status by Bowman and Harris (1984, supplement 1993) – this lists depositaries. This is held by all the Inns of Court Libraries.
  •  Multilateral treaty calendar 1648-1995 by Wiktor. It is a chronological list of multilateral treaties, published in 1998. Information is given on where a treaty has been published, its entry into force and depository.

What are “travaux preparatoires” and where can I find them?

  • “Travaux preparatoires” (literally “preparatory works”) is the commonly found French term for what are called in English “preparatory materials”. They provide an official record of the negotiation of a treaty, and may be helpful in clarifying a treaty’s intention.
  • If they are published, they will generally be available from the depositary, or may be placed on any official site for the treaty.

 How are UK treaties published?

  • Once the UK has ratified a treaty, the text is included in the United Kingdom Treaty Series. The treaty is then published by The Stationery Office as a Command Paper. The treaty will have a Treaty Series number and a Command Paper number. For citation purposes, the Command Paper number is more important.

 Free web sources

  • Official Documents – includes Command Papers in full text from 17 May 2005 to January 2014. Earlier Command Papers from 1994 to April 2005 can be found via the About Official Documents New Command Papers can be found on the GOV.UK: Publications site.

Hard copy sources

  • The following Inn Libraries hold Command Papers: Inner Temple (1940/41 onwards); Lincolns Inn (1833 onwards).

Back to top.

Where will I find the text of UK treaties?

 Free web sources

  • UK Treaties – this section of the GOV.UK website provides information on the work of the Foreign & Commonwealth Office (FCO) Treaty section. There is a UK Treaties Online (UKTO) database containing records and full texts of treaties published since 1892. Most texts are held within the database itself: others may be found by following the links provided.
  • Official Documents – includes Command Papers in full text from 17 May 2005 to January 2014. Earlier Command Papers from 1994 to April 2005 can be found via the About Official Documents New Command Papers can be found on the GOV.UK: Publications site.

 Hard copy sources

  • The following Inn Libraries hold Command Papers: Inner Temple (1940/41 onwards); Lincolns Inn (1833 onwards).
  • The Inner Temple Library holds British and Foreign State Papers (BFSP) which includes treaties, 1812-1968. Middle Temple holds BFSP 1812-1968 and Lincolns Inn 1812-1832/33.
  • Hertslet’s Commercial Treaties (HCT) – covers 1827-1925. Inner Temple, Lincoln’s Inn and Middle Temple Libraries hold this series.
  • Index to British Treaties by Parry. This has 3 volumes and covers all treaties from 1101 to 1968. A fourth volume covers 1969-88 and updates the previous 3 volumes. This is arranged chronologically by date of signature. There are subject and country indexes. Command Paper numbers and other citations are given. All the Inns of Court Libraries have this publication.
  • Multilateral Treaties: Index and Current Status by Bowman and Harris. First published in 1984 with supplements covering the period up to 1st January 1994. It includes multilateral treaties where the UK is a party. It is arranged chronologically by date of signature. There is a subject index and an index of keywords used in the treaty title. Command Paper numbers and other citations are given. Inner Temple, Lincolns Inn and Gray’s Inn Libraries have this work.
  • Textbooks – the texts of treaties are sometimes found in textbooks, e.g. Brownlie: Basic Documents on Human Rights; Singh: International Maritime Law Conventions; Copinger and Skone James on Copyright; Shawcross and Beaumont on Air Law; Simons Direct Tax Service.
  • Acts and Statutory Instruments – the schedules to Acts and SIs may contain the text of treaties if the treaty is incorporated into domestic law by the piece of legislation.
  • Indexes to government publications – these can be used to track down Command Papers.

Back to top.

Where will I find the text of treaties to which the UK is not a party?

 Free web sources

  • United Nations Treaty Series Online Collection – contains a collection of treaties and international agreements registered or filed and recorded with and published by the Secretariat since 1946. It also includes a collection of treaties and subsequent treaty actions registered with and published by the Secretariat of the League of Nations between 1920 -1944.
  • Flare Index to Treaties – this site has information on over 2,000 of the most significant multilateral treaties. Each entry includes information about where the full text of each treaty can be found in print with live links to electronic versions on the internet, where available. The index covers treaties concluded between 1353 and the present. Searching can be done using subject keywords, words from the official or popular title, the reference number allocated to a treaty by either the Council of Europe or the International Labour Organization, the date on which the treaty was concluded (either the precise date or just the year), or the place where the treaty was concluded.
  • Websites of international organisations – some organisations act as depositaries or secretariats for certain multilateral treaties e.g. Hague Conference on International Law, WIPO etc.

National websites

 Hard copy sources

  • Multilateral Treaties: Index and Current Status by Bowman and Harris (1984, supplement 1993) for multilateral treaties whether UK is a party or not. Command Paper numbers and other citations are given. Inner Temple, Lincolns Inn and Gray’s Inn Libraries have this work.
  • Multilateral Treaty Calendar by Wiktor, 1648 -1995 – details are given as to where the printed text can be found. Inner Temple and Lincoln’s Inn Libraries have this book.
  • UN Treaty Series – all treaties made by members of the UN have to be registered with the UN Secretariat and published by it. Middle Temple Library has the UN Treaty Series in hard copy. There are chronological and alphabetical indexes to this.
  • League of Nations Treaty Series 1920-1946 – predecessor to the UN Treaty Series. Middle Temple Library has this.
  • International Legal Materials – this journal contains the texts of selected treaties. Inner Temple and Gray’s Inn Libraries have this series, 1962 onwards.

Back to top.

Where will I find national collections of treaties?

How can I find EU treaties?

Free web sources

  • Council of Europe Treaty Office – has full text and summaries of the complete European Treaty Series (ETS) 1949-2003, and its continuation the Council of Europe Treaty Series (CETS) 2004 onwards.

Hard copy sources

  • Official Journal of the European Union L series – has the text of treaties entered into by the EU. This is held by Gray’s Inn and Middle Temple Libraries.
  • European Conventions and Agreements (Council of Europe) – held by Inner Temple and Middle Temple Libraries, 1949 onwards.
  • Europaische Vertrage = European treaties = Traites europeens (Council of Europe) – held by Inner Temple Library.

Back to top.

How can I check the status and the parties to a treaty?

  • The official source of information on the status of a treaty (which parties have ratified or acceded, what date it comes into force, what reservations particular parties have made etc.) is the depositary body named in the treaty. The depositary body can be consulted if the information is not easily found in the published indexes, online or in the treaty itself.

 Free web sources

  • UK Treaties Online – provides access to details of over 14,000 treaties involving the UK. You can research the existence of treaties, find important information about them (such as the place and date of signature and entry into force date) and see which states or organisations participate in them.
  • United Nations Treaty Collection website – this section of the UN website provides information on the status of over 500 major multilateral instruments deposited with the Secretary-General of the United Nations.
  • Council of Europe Treaty Office – includes a chart of signatures and ratifications and a list of declarations, reservations and other communications. This provides both full text and summaries of the complete European Treaty Series (ETS) 1949-2003, and its continuation the Council of Europe Treaty Series (CETS) 2004 onwards.

Hard copy sources

  • Multilateral Treaties: Index and Current Status by Bowman and Harris (1984, supplement 1993) – this will give information on entry into force, duration, reservations, parties, signatories.
  • Index to British Treaties by Parry (1970) – gives information on the date of signing, entry into force, duration and parties.
  • Multilateral Treaty Calendar by Wiktor (1998) – gives information on the date of signing, entry into force, parties, duration etc.
  • The texts mentioned above are not up to date. Contact the FCO to get up to date status information for UK treaties. The FCO contact details are: email: treatypublicenquiries@fco.gov.uk.

Back to top.

What is the procedure for treaties that involve UK dependencies and overseas territories?

 The UK government is responsible for the defence and international relations of dependent and overseas territories. Given this the UK signs treaties on their behalf. However, the dependencies and overseas territories must be given time to consider the terms of the treaty. The UK will then ratify the treaty on behalf of the territory or dependency.

Free web sources

What are the contact details for the Foreign & Commonwealth Office (FCO)?

FCO Treaty Enquiry Service (which is free of charge) is open from 0900 to 1700 Monday to Friday

This service can give advice on whether a treaty has entered into force, details of the signatories and contracting parties, together with dates of signature, ratification, approval, acceptance, accession, succession and withdrawals or denunciations. Reservations, declarations or objections can usually be identified, and where applicable, the depositary.

Email: treatypublicenquiries@fco.gov.uk

Back to top.

Database Coverage

What are the coverage dates for the websites?

Council of Europe Treaty Office – covers the complete European Treaty Series (ETS) 1949-2003, and its continuation the Council of Europe Treaty Series (CETS) 2004 onwards.

FCO archived website, Treaties – links to the full text of treaties published 1999 to 2012. There is also a list of the multilateral treaties for which the UK government is the depositary.

 FCO archived website, Treaty Links – this section of the site contains information on States’ websites with treaty information.

 FCO archived website, UK Overseas Territories – has information on the procedures for the extension of treaties to overseas territories and the texts of treaties to which the overseas territories are party.

 Flare Index to Treaties – contains over 1,500 of the most significant multilateral treaties from 1856 to the present.

 Official Documents – includes Command Papers in full text from 17 May 2005 to January 2014. Earlier Command Papers from 1994 to April 2005 can be found via the About Official Documents link. New Command Papers can be found on the GOV.UK: Publications site.

 UK Treaties – is a section of the GOV.UK providing information on the work of the Foreign & Commonwealth Office (FCO) Treaty section. There is a UK Treaties Online (UKTO) database containing records and full texts of treaties published since 1834. Most texts are held within the database itself: others may be found by following the links provided.

 United Nations Audiovisual Library of International Law – covers national collections of treaties, which can be found via the Research Library link.

United Nations Treaty Series – includes United Nations Treaty Series (1946-) and the earlier League of Nations Treaty Series (1920-1944).

Back to top.