How hard is the national investigators' exam?
The honest answer is in the College of Policing's own published results, which most candidates never go looking for. Here's what recent sittings actually show, and why the exam is built to be hard in specific, structural ways.
The short answer
Across the five most recently published sittings, pass rates have ranged from 53.2% to 63.7%. On average, that means roughly four candidates in ten did not pass — even in the strongest of those five sittings, more than a third of candidates missed the pass mark. It is not an exam most people can walk into unprepared and clear comfortably.
Source: College of Policing "Results and analysis overview" reports, per sitting — see the table below for each one.
Pass rates by sitting
| Sitting | Candidates | Passed | Pass rate |
|---|---|---|---|
| September 2023 | 1,397 | 743 | 53.2% |
| March 2024 | 1,795 | 1,079 | 60.1% |
| March 2025 | 1,612 | 941 | 58.4% |
| September 2025 | 1,318 | 792 | 60.1% |
| March 2026 | 1,633 | 1,040 | 63.7% |
These are the recent sittings with published results reports we could verify, not a claim that every sitting is listed. Each report also breaks results down by force, sex and ethnicity — the College publishes those breakdowns; this page doesn't reproduce the force-level tables.
Why it is hard, structurally
Put the pass rates aside for a moment — the exam is built to be difficult in a few specific ways, independent of how any one sitting turns out.
- Breadth. The syllabus is drawn solely from the current-year edition of Blackstone's Police Investigators' Manual, across the whole of it, not a predictable subset — there's no way to narrow down what will and won't come up.
- Application, not recall. Questions are set as scenarios you have to reason through, rather than facts you can simply recognise on the page.
- Time pressure. Eighty questions in two hours works out to roughly 90 seconds a question on average, with no time built in to dwell.
- A fixed cut, not a curve. The pass mark is set at 55.7% in advance. Your result depends only on your own score against that number, not on how anyone else in your sitting performs.
- Ten questions removed after the fact. The paper has 80 questions, but 10 are removed from marking afterwards — the marking panel strikes the ten questions that performed least well, to keep the paper a fair test. Candidates are never told which, and there's no appeal on that removal.
Source: College of Policing NIE candidate handbook 2026, sections "Examination structure and syllabus" and "Pass mark".
What makes it passable
None of the above means the exam is unbeatable — it means the difficulty is specific, and specific difficulty can be prepared for directly.
A fixed pass mark is, in one sense, a gift: you know exactly what target you're working towards (39 out of 70), rather than needing to outscore a shifting cohort. The College's own candidate handbook recommends a minimum of 14 weeks of independent study, which is a realistic floor rather than a token gesture. And because the exam tests application under time pressure rather than recognition, the most direct preparation is repeated recall practice — testing yourself under conditions similar to the exam — rather than rereading the manual, which builds familiarity with the material but not the ability to produce it quickly under pressure.
Source: College of Policing NIE candidate handbook 2026, "Overview" and "Pass mark".
Frequently asked
What is the pass rate for the national investigators' exam?
It varies by sitting. In the most recently published results, from March 2026, 1,040 of 1,633 candidates passed — 63.7%. Across the five most recently published sittings, the pass rate has ranged from 53.2% (September 2023) to 63.7% (March 2026), averaging around 59%, so on average roughly four candidates in ten did not pass.
Is the national investigators' exam harder than other police exams?
There's no honest comparison to make. The College of Policing publishes detailed results reports for this exam, but equivalent published pass-rate data for other police promotion or specialist exams isn't available in the same form, so any claim that it's harder or easier than another exam would be a guess dressed up as a fact.
What happens if I fail the national investigators' exam?
Resits are governed by your own force's policy, not a single national rule. After a second fail you can expect a development meeting to look at what went wrong, and a third fail typically triggers a wider review of your investigative career pathway.
Is the national investigators' exam pass mark curved?
No. The pass mark is fixed at 55.7%, which is 39 correct answers out of the 70 that are marked. It doesn't move based on how other candidates in your sitting perform — your result depends on your own score against that fixed cut, though the handbook does let the College's debrief panel adjust the mark in exceptional circumstances.
Practise the way the exam is actually marked
NIE Revision is 513 revision cards and 769 scenario-format practice questions weighted like the real paper, with mock exams and a readiness estimate against the 55.7% pass mark. £29 one-off, no subscription, no expiry.