Seven referencing mistakes that quietly cost marks

Referencing can feel like a boring technical detail, but markers notice it. Accurate, consistent citations show care and academic honesty. Scattered errors suggest the opposite, even when your ideas are strong. Poor referencing can also lead to accidental plagiarism, which is far more serious than losing a few marks.

Here are seven of the most common mistakes, with examples mainly in APA 7th edition, one of the most widely used styles. Always check your own department's guide, because many universities use their own version of a style.

1. Mixing referencing styles

Using APA in one section and Harvard in another, or copying references from different websites without adjusting them, creates inconsistency. Pick the style your department requires and apply it everywhere.

2. Citations and reference list don't match

Every source you cite in the text must appear in your reference list, and every entry in the list must be cited in the text. This is one of the easiest mistakes to fix, and one of the most common.

3. Getting 'et al.' wrong

In APA 7, for sources with three or more authors, you use the first author's name followed by 'et al.' from the very first in-text citation. In the reference list, however, you list up to 20 authors.

4. Formatting DOIs incorrectly

A DOI (digital object identifier) is a permanent link to an article. In APA 7, it should be written as a full web address, in lower case, with no full stop at the end.

5. Missing page numbers for direct quotes

When you quote a source word for word, most styles require a page number (or paragraph number for sources without pages). For example: (Smith, 2019, p. 45). Paraphrasing usually does not require one, although some departments encourage it.

6. Forgetting the hanging indent

In APA and many other styles, each reference list entry uses a hanging indent: the first line starts at the margin and the following lines are indented (about 1.27 cm or 0.5 inches). Word processors do not do this automatically. Set it in your paragraph settings, not with spaces or tabs.

7. Trusting your reference manager blindly

Tools like Zotero, Mendeley and EndNote save huge amounts of time, but their output is only as good as the information saved. Common problems include titles in the wrong capitalisation, missing issue numbers and author names saved incorrectly. Always check the final list by eye.

Bonus: citing sources you haven't read

If you read about a study in another book or article but did not read the original yourself, you should make that clear. This is called secondary citation. In APA, you would write something like: (Brown, 1998, as cited in Smith, 2019). Only Smith goes in your reference list. Where possible, try to find and read the original source.