The United Nations Treaty Collection (UNTC) is a free website, accessible to all.
The website covers treaties registered with the UN under article 102 of the Charter, together with League of Nations Treaties. It also provides status information for the 500 or so multilateral treaties deposited with the UN Secretary-General. Several key UN publications relating to treaties are available as well.
United Nations Treaty Series (1946 - ): treaties registered under article 102; more than 158,000 in number, bilateral and multilateral.
The League of Nations Treaty Series (1920 - 1944)
Multilateral Treaties Deposited with the Secretary-General (MTDSG): covers the relatively small number of treaties for which the UN is the official depositary. Includes:
Status of Treaties database: details of signatures, ratifications and so on, with links to the full text
Certified True Copies: the official copy of each deposited treaty
Titles and Recent Texts: lists of treaty titles, together with the texts of recently deposited treaties
Monthly Statement (MS): official bulletin giving details of treaties registered under article 102 (May 1998 - )
The Publications page of the UNTC website provides the full text of key titles such as theTreaty Handbook and Summary of Practice of the Secretary-General as Depositary of Multilateral Treaties
TIPS: The search facilities can be slow to respond, so be prepared to wait for the results to display.
Some of the search screens require you to click on "Add" to insert your search term into the search box; if you forget to click on "Add", the search will not work.
The MTDSG Status of Treaties database has a contents page arranged by broad subject area; it can be easier to browse the database from here, rather than using the search facilities. There is an Advanced Search screen and a Full Text search screen.
The UN Treaty Series database can be searched by popular name, title, participant and other criteria; it also has an Advanced Search Screen and a Full Text search screen.
The League of Nations Treaty Series database offers Basic and Advanced search screens.
The Monthly Statement database offers Advanced and Full Text search screens.
There is a help page for the UNTS and LNTS databases.