UK Treaties

Guidance about the work of the Foreign, Commonwealth & Development Office (FCDO) Treaty Section.


The FCDO Treaty Section supports other government departments with the conclusion of treaties.

We also provide information on those treaties to which the UK is or has been a party. This includes running the UK Treaties Online (UKTO) database and providing our Treaty Enquiry Service.

You can follow updates to treaties involving the UK by our treaty action bulletins.

Searching for treaties

UKTO contains the details of around 15,000 treaties involving the UK.

The Treaty Enquiry Service may be able to help if you cannot find what you are looking for, but please note we are not able to provide legal advice, interpretation of treaty texts, or undertake research on your behalf:


Locating treaty texts

Treaties that have entered into force

Treaties must be laid before the Houses of Parliament as command papers. Once a treaty has entered into force it is published in our Treaty Series:

Series Description Links
Treaty Series Agreements that have completed all necessary procedures and are now in force for the UK Full details and papers from 1892 to present available on UKTO

Quick reference: Treaty Series 2013 - 2017

Treaty Series 2018 to present

Treaties that have been signed but not yet ratified (or equivalent)

Series Description Links
Country Series Bilateral agreements not yet in force Papers from 1999 to 2012 available on our archived treaty command papers site

Country Series 2013 onwards
European Union Series Multilateral agreements between member states of the European Union, or between third parties and member states of the European Union, not yet in force for the UK Papers from 1999 to 2012 available on our archived treaty command papers site

European Union Series 2013 to 2018
Miscellaneous Series Multilateral agreements, where the UK is a signatory, not yet in force Papers from 1999 to 2012 available on our archived treaty command papers site

Miscellaneous Series 2013 onwards

Other resources

If the command paper you are looking for is not available using any of these Series links, the UK Parliamentary Papers site may be of assistance. It is best to search using the command paper number. This number is under the ‘Publication Records’ section of the treaty you are looking at on UKTO (for example: ‘Cmnd 1234’).

Multilateral treaties

For multilateral treaties where the UK is not the depositary, we recommend you check their current status with the depositary government or authority.

Lists of treaties and selected non-treaty command papers

We have prepared lists of treaties and related measures that may apply in certain circumstances:

Practice and procedures for new treaties

The responsibility for concluding treaties involving the UK lies with the Secretary of State for Foreign, Commonwealth and Development Affairs. This remains the case even when the negotiation of the treaty is led by another government department.

The FCDO’s Legal Advisers and Treaty Section:

  • must be given the opportunity to comment on the drafts of all treaties under negotiation
  • will advise on the form and substance of the treaty, though not substance which is technical and of which the other government department is the expert
  • will advise on related matters such as the production of Full Powers and instruments of ratification
  • will produce original signature copies of treaties and advise on the treaty signing ceremony
  • will arrange for the treaty to be published and laid before Parliament
  • are responsible for the registration of these treaties with the UN, allowing their subsequent publication in the United Nations Treaty Series, and
  • will transfer treaties to The National Archives for preservation

Our specific guidance on practice and procedure provides further information, including the procedures for ratification under the Constitutional Reform and Governance Act (CRaG Act) 2010.

UK Crown Dependencies and Overseas Territories

Unless expressly authorised to do so by HMG in the UK, Crown Dependencies and Overseas Territories do not have the authority to become a party to treaties in their own right. The UK must extend the territorial scope of its ratification of treaties to include them. This is normally done either at the time of ratification, or at some later date.

We have published complete guidance on extension of treaties.

The UK as depositary

The UK acts as depositary for multilateral treaties encompassing a wide range of subjects. We have published a list of the treaties for which the UK is depositary, accompanied by individual status lists.

Treaty Section is responsible for coordinating the UK’s response to formal instruments of ratification, accession or otherwise to these treaties which are deposited with the FCDO by foreign governments or international organisations. In most cases, treaties take effect for a new party either on the day an instrument of ratification or equivalent is deposited with the FCDO, or after a pre-determined period has elapsed in accordance with the provisions of the treaty concerned.

Those wishing to deposit an instrument with the FCDO should ensure it is sent to us via e-copy with the original hard copy posted to the following address:

Treaty Section
(Legal Directorate)
Room WH.2.143
King Charles Street
Foreign, Commonwealth & Development Office


The FCDO is not responsible for the contents or reliability of the linked websites, and does not necessarily endorse the views expressed within them. Listing shall not be taken as endorsement of any kind. We cannot guarantee that these links will work all of the time and we have no control over availability of the linked pages.

Any information provided is for convenience only, and is based on information supplied by the depositary concerned. Treaty Section accepts no responsibility for any inaccuracies or omissions contained therein. It is recommended that status information be confirmed with the depositaries for each agreement.

Updates to this page

Published 2 July 2013
Last updated 7 November 2019 + show all updates
  1. Updated guidance covering the work of Treaty Section.

  2. Added list of countries that have ratified the Vienna Convention on Consular Relations.

  3. First published.

  4. added April 2013 bulletin of recent changes to UK treaties in force

  5. Added latest editions of the supplementary list.

  6. added treaty command series papers in a table with links to the 4 document series.

  7. contact details for enquiries service added

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