To cite a treaty, you need its official title, the parties (for bilateral agreements), the signing date, and the treaty series where the full text was published, then arrange those elements according to your citation style. Bluebook, APA, MLA, and Chicago each order and punctuate the same core facts differently, but the underlying information is the same across all four.
What You Need Before You Start
Pull these details from the treaty itself before you format anything:
- The official title as it appears at the top of the first page, such as “Convention on the Rights of the Child.”
- The parties. A bilateral treaty has two; a multilateral treaty has three or more. Bilateral citations name both parties. Multilateral citations do not list signatories.
- The date of signing. If the treaty was opened for signature over a span of time rather than signed on a single day, use the date it was opened for signature, adopted, or approved. The date the treaty entered into force is separate and may appear in a parenthetical, but it does not replace the signing date.
- The treaty series and source. For U.S. treaties, that is United States Treaties and Other International Agreements (U.S.T.), which compiled bound volumes from 1950 through 1984, and the Treaties and Other International Acts Series (T.I.A.S.), the official publication format since 1945. For international agreements more broadly, the United Nations Treaty Series (U.N.T.S.) publishes registered treaties with a volume and page number.1United States Department of State. Finding Agreements
- The volume and page number that pinpoint the treaty within its series.
Bluebook Format
Rule 21 of The Bluebook governs treaties and other international agreements.2The Bluebook Online. 21 International Materials The sequence is: (1) the name of the agreement, (2) the parties if bilateral, (3) any subdivisions you are citing, (4) the date of signing, and (5) the source. The treaty name is set in regular type, not italics.
Bilateral Treaties
Name both parties after the title, abbreviated according to Table T10 and separated by a hyphen. Then add the signing date, volume number, series abbreviation, and starting page:
Treaty of Friendship, Commerce and Navigation, Japan-U.S., art. XI, ΒΆ 1, Apr. 2, 1953, 4 U.S.T. 2063.
When more than one source carries the treaty, follow this preference order and cite only the highest available: U.S.T. (or Stat.), then T.I.A.S. (or T.S. or E.A.S.), then U.N.T.S., then Senate Treaty Documents or Senate Executive Documents, then Department of State Dispatch, then Department of State Press Releases.
Multilateral Treaties
Skip the party list. Move directly from the title to the date and source. If the treaty was not signed on a single date, indicate the date it was opened for signature in italics:
North Atlantic Treaty art. 5, Apr. 4, 1949, 63 Stat. 2241, 34 U.N.T.S. 243.
Treaties the United States Did Not Join
Cite a source published by an international organization, such as U.N.T.S., the League of Nations Treaty Series (L.N.T.S.), or the European Treaty Series (E.T.S.). If the treaty does not appear in any of those, cite the official source of one signatory with a parenthetical identifying that country. International Legal Materials (I.L.M.) or another unofficial source is a last resort.
Short Forms in Later Footnotes
After the full citation, use a shortened form. If the treaty has a long or well-known name, add a bracketed “hereinafter” tag at the end of the first citation, for example [hereinafter Geneva Protocol]. Then use the short name with “supra” and the original footnote number:
Geneva Protocol, supra note 1, at 572.
When the same treaty was cited in the immediately preceding footnote, use “id.” in place of supra.
APA Format
APA’s 7th edition defers to Bluebook conventions for legal materials, so treaty citations borrow from legal style rather than follow the standard author-date reference template.3Purdue OWL – Purdue University. APA Formatting and Style Guide 7th Edition Legal References The reference list entry follows this pattern:
Name of Treaty or Convention, Month Day, Year, URL
For example:
International Covenant on Civil and Political Rights, December 16, 1966, https://www.ohchr.org/en/instruments-mechanisms/instruments/international-covenant-civil-and-political-rights
The title appears in title case and is italicized. The signing date follows the title, separated by a comma, not placed in parentheses. If a URL is available, it closes the entry, with no period after it.
In-Text Citations
Cite the treaty by title and year. Both can sit in parentheses at the end of the sentence, as in (Treaty Concerning Pacific Salmon, 1985), or the title can appear in your prose with just the year in parentheses. Long titles can be shortened after the first use as long as the shorter form clearly identifies the treaty.
The UN Charter
The full UN Charter does not require a reference list entry. Mention it by name in the text. To cite a specific provision, create a reference entry and in-text citation in this form: U.N. Charter art. 51. Add “para.” with the paragraph number for a specific paragraph within an article.3Purdue OWL – Purdue University. APA Formatting and Style Guide 7th Edition Legal References
MLA Format
MLA’s 9th edition treats a treaty as a source within its container system. The Works Cited entry opens with the treaty’s formal name in place of an author, since no single author exists. The signing date follows the title. If the treaty appears in a larger collection such as the United Nations Treaty Series, that series is the italicized container.
Works Cited Entry
A basic MLA entry lists the treaty title (as the “author”), the signing date, the container, and a location element such as volume, page number, or URL. Periods separate the major elements; commas separate items inside a single element:
Convention on the Rights of the Child. 20 Nov. 1989. United Nations Treaty Series, vol. 1577, p. 3.
If you accessed the treaty through an online database like HeinOnline or a government website, that database or site becomes a second container. Italicize its name and add the URL or DOI. MLA does not require an access date, though including one is acceptable for digital sources that may change.
In-Text Citations
The parenthetical uses the treaty title, or a clearly recognizable short version, to point back to the Works Cited entry, for example (Convention on the Rights of the Child). Keep any shortened form specific enough that the reader can find the right entry.
Chicago Style
Chicago uses two systems: Notes-Bibliography, common in history and the humanities, and Author-Date, common in the sciences. Both place the treaty title in quotation marks rather than italics.
Notes-Bibliography
The footnote or endnote lists the title in quotation marks, a comma, the date information (such as “opened for signature December 9, 1948”), the publication source with volume and page, and a URL if applicable. The bibliography entry uses the same elements but replaces the internal commas with periods between the major sections:
Note: “Convention on the Prevention and Punishment of the Crime of Genocide,” opened for signature December 9, 1948, 78 U.N.T.S. 277.
Bibliography: “Convention on the Prevention and Punishment of the Crime of Genocide.” Opened for signature December 9, 1948. 78 U.N.T.S. 277.
Bilateral vs. Multilateral in Chicago
For a bilateral treaty, name both signatory parties in or right after the title. For a multilateral treaty, the title alone identifies the agreement. The Author-Date system uses the same elements but places the year prominently after the title so it can be picked up by in-text references.
Recent Treaties Not Yet in the Standard Series
Not every treaty appears in the printed series. U.S.T. stopped compiling bound volumes after 1984, and many recent agreements exist only through the State Department’s T.I.A.S. electronic releases or government websites.4Library of Congress. United States Treaties and Other International Agreements About This Collection When a treaty has not yet appeared in a preferred series, the Bluebook fallback order is:
- International Legal Materials (I.L.M.), a widely available secondary compilation of significant international documents.
- Government and intergovernmental organization websites, including electronic databases and the State Department’s online T.I.A.S. releases.
- Historical or unofficial compilations such as the Foreign Relations of the United States series, Parry’s Consolidated Treaty Series, or Hein’s microfiche treaty service.
- Books or periodicals, only when no other source carries the text.
APA and MLA handle this more simply. Both allow (and often prefer) a direct URL, so citing a recent treaty from a government website or the UN’s online treaty collection just means appending the URL as the final element of the reference or Works Cited entry.
Mistakes That Trip People Up
- Confusing the signing date with the entry-into-force date. Most styles ask for the signing date. Add the effective date in a parenthetical if it matters to your argument, but do not swap it in.
- Listing parties for a multilateral treaty. Bluebook, APA, and Chicago all omit individual parties for multilateral agreements. Only bilateral treaties name them.
- Citing the wrong series. If the treaty appears in U.S.T., cite U.S.T., not T.I.A.S. or U.N.T.S. Follow the preference hierarchy for the style you are using.
- Adding a period after a URL. In APA, no period follows a URL at the end of a reference entry, and a trailing period can break the hyperlink.
- Italicizing the treaty name in Bluebook. Bluebook uses regular type for treaty names. APA italicizes the title. Chicago puts it in quotation marks. MLA leaves the title in plain text and italicizes the container.