Harvard referencing adjusts how you present author names based on how many authors a source has. One author is straightforward — surname and year. Two authors are joined with "and." Three or more authors trigger the et al. rule, though the exact threshold varies by institution. The reference list, however, always spells out every author's name (up to a limit set by your guide).
One Author — The Baseline
A single-author source is the simplest case. It establishes the pattern everything else builds on:
In-text citations:
Parenthetical:(Walker, 2017, p. 40)
Narrative:Walker (2017, p. 40) argues that…
Reference list:
Walker, M. (2017) Why we sleep: the new science of sleep and dreams. London: Penguin Books.
Two Authors
List both authors in every citation — you never use et al. for two-author sources.
In-Text Citations
Parenthetical:(Kahneman and Tversky, 2000)
Narrative:Kahneman and Tversky (2000) demonstrate that…
Use "and" between the two names. Some Harvard guides use "&" instead — e.g., (Kahneman & Tversky, 2000). Follow your institution's convention and be consistent throughout your paper.
Reference List
Kahneman, D. and Tversky, A. (2000) Choices, values, and frames. Cambridge: Cambridge University Press.
In the reference list, list both authors with their initials. Use "and" (or "&" if your guide requires it) between them.
Three Authors
This is where institutional variation becomes significant. There are two common conventions:
Convention A — List All Three on First Use, Then Et Al.
First citation:
(Rahman, Torres and Kim, 2021)
Subsequent citations:
(Rahman et al., 2021)
Convention B — Et Al. From the First Citation
Every citation:
(Rahman et al., 2021)
Your institution's Harvard guide will specify which convention to follow. Convention A is more traditional; Convention B is becoming more common (and mirrors APA 7th edition). If your guide is silent on this point, Convention A is the safer choice.
Reference List
Regardless of which in-text convention you use, the reference list always includes all three authors:
Rahman, S., Torres, M. and Kim, J. (2021) Global health policy: challenges and responses. Bristol: Policy Press.
Four or More Authors
For sources with four or more authors, use et al. from the very first citation. There is virtually no institutional variation on this rule — it applies across all Harvard guides.
In-Text Citations
Parenthetical:(Nguyen et al., 2022)
Narrative:Nguyen et al. (2022) argue that urban sustainability requires…
Reference List
List all authors, regardless of how many there are:
Nguyen, H., Park, S., Li, W. and Fernandez, C. (2022) Urban sustainability: theory and practice. New York: Routledge.
Note:Some institutions set a cap on the number of authors to list in the reference list — for example, "list up to 6 authors, then use et al." This is relatively unusual in Harvard guides, but check yours. The default rule is to list everyone.
What About Very Large Author Lists?
In the sciences, papers can have dozens of authors. Most Harvard guides still require you to list all of them in the reference list. If your institution sets a cap, it will look something like this:
Chen, A., Davis, B., Evans, C., Garcia, D., Holm, E., Ibrahim, F. et al. (2023) 'Title of the article', Journal Name, 45(2), pp. 100–115.
Only do this if your guide explicitly allows it. Otherwise, list every author.
How Et Al. Works — The Details
Et al. is short for et alia (Latin for "and others"). A few rules:
- Italicise et al. in some guides; others leave it in roman. Check your convention.
- Always include the full stop after "al." — it's an abbreviation.
- Et al. replaces all names except the first author's.
- Never use et al. in the reference list (unless your institution explicitly allows it for very long author lists).
Avoiding Ambiguity With Et Al.
If you're citing two different sources that shorten to the same et al. form — for example:
Smith, Jones and Williams (2020)
Smith, Brown and Lee (2020)
Both would become (Smith et al., 2020). If this ambiguity arises, list enough authors to distinguish them, even if you'd normally use et al.:
(Smith, Jones et al., 2020)
(Smith, Brown et al., 2020)
This makes clear which source you're referring to. Most Harvard guides recommend this approach; APA has a similar rule.
Corporate and Organisational Authors
When a source is published by an organisation rather than a named individual, the organisation's name acts as the author:
In-Text Citations
Parenthetical:(World Health Organization, 2024)
Narrative:The World Health Organization (2024) recommends that…
If the name is long and you reference it multiple times, introduce an abbreviation on first use:
First citation:(Department for Education [DfE], 2023)
Subsequent citations:(DfE, 2023)
Reference List
Department for Education (2023) School workforce census 2022. London: HMSO.
World Health Organization (2024) Mental health. Available at: https://www.who.int/health-topics/mental-health (Accessed: 15 January 2025).
Use the organisation's full name — don't abbreviate it in the reference list, even if you used an abbreviation in the text.
Editors as Authors
When you reference an edited book as a whole (not a specific chapter), the editor(s) take the author position with (ed.) or (eds.):
One Editor
Morris, T. (ed.) (2019) Digital education strategies. Oxford: Oxford University Press.
In-text:(Morris, 2019)
Two or More Editors
Patel, R. and Wong, L. (eds.) (2021) Contemporary issues in public health. London: Sage.
In-text:(Patel and Wong, 2021)
When citing a specific chapter in an edited book, the chapter's author is the main author and the editor appears in the middle of the reference:
Lane, K. (2019) 'Cognitive load in online learning', in Morris, T. (ed.) Digital education strategies. Oxford: Oxford University Press, pp. 112–134.
In-text:(Lane, 2019, p. 118)
For full details on book citations, see How to Reference a Book in Harvard Style.
Quick-Reference Table
| Number of Authors | In-Text (First Use) | In-Text (Subsequent) | Reference List |
|---|---|---|---|
| 1 | (Walker, 2017) | (Walker, 2017) | Walker, M. (2017) … |
| 2 | (Kahneman and Tversky, 2000) | (Kahneman and Tversky, 2000) | Kahneman, D. and Tversky, A. (2000) … |
| 3 | (Rahman, Torres and Kim, 2021) or (Rahman et al., 2021) | (Rahman et al., 2021) | Rahman, S., Torres, M. and Kim, J. (2021) … |
| 4+ | (Nguyen et al., 2022) | (Nguyen et al., 2022) | Nguyen, H., Park, S., Li, W. and Fernandez, C. (2022) … |
| Corporate | (World Health Organization, 2024) | (WHO, 2024) — if abbreviated on first use | World Health Organization (2024) … |
| Editor(s) | (Morris, 2019) | (Morris, 2019) | Morris, T. (ed.) (2019) … |
Harvard vs. APA — How Author Rules Differ
Since both Harvard and APA use the author-date system, students often confuse their multi-author rules. Key differences:
| Rule | Harvard (Common UK Convention) | APA (7th Edition) |
|---|---|---|
| Two authors in text | "and" or "&" (varies) | "&" in parentheses, "and" in narrative |
| Three authors | List all or et al. (varies) | Et al. from first citation |
| Et al. threshold | 3 or 4 authors (varies) | 3+ authors |
| Ampersand in reference list | "and" or "&" (varies) | Always "&" |
For a detailed comparison, see Harvard vs. APA — What's the Difference?.
What's Next?
Now that you understand multi-author citations, explore these related guides:
- Harvard In-Text Citations — the complete guide to parenthetical and narrative citations
- Harvard Reference List — formatting rules for the reference list, including how to order same-author entries
- How to Reference a Book in Harvard Style — detailed formats for edited books, chapters, and multi-author works
