Most UK universities run submissions through detection software — commonly Turnitin — but these tools are unreliable in both directions. A flag isn't proof, and a clean score isn't a guarantee.
For a student who wrote their own work, the bigger risk is being wrongly flagged. That's the thing worth preparing for.
What's actually running on your submission
When you upload to Turnitin, two separate things happen. The similarity report matches your text against a corpus of published and previously-submitted work — that's the long-established plagiarism check. Alongside it, an AI writing indicator produces a percentage estimate of how much of the document reads as machine-generated. Your marker usually sees both. You usually see neither, or only the similarity figure, depending on how the module was set up.
Some departments layer on other tools, and plenty of markers rely on something more reliable than either: a lecturer who has read your work before will notice immediately if your voice has changed.
Why the score isn't the answer you want
Detectors measure how predictable writing is, not whether a machine produced it. Careful, formal or second-language writing trips them even when it's entirely your own — a Stanford study found roughly 61% of essays by non-native English speakers were wrongly flagged. It runs the other way too: text that has been deliberately varied often sails through. A tool that errs in both directions isn't measuring what its name claims.
A detector score should never be sufficient evidence of misconduct on its own.HEPI, August 2026
Some universities abroad dropped their detectors in 2025–26 as too unreliable to act on. Most UK institutions still use them. That's the awkward middle we're in: the tools aren't trustworthy, and they're still switched on.
What you can actually control
Not your university's software. But you can:
- See it first. Read your essay the way a detector does and rewrite anything that reads oddly — in your own voice, because it's clearer, not to beat a tool.
- Keep your working. Drafts, notes and version history in one continuously-edited document. If you're ever asked, that answers it.
- Know your policy. The rules on your assignment brief are the ones that apply, whatever the general practice is.
If you've already been flagged, start with what to do when you're wrongly accused. For the full technical picture, our guide on how Turnitin's AI detection works goes considerably deeper than this page does.
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