Contents
In brief
- 1.The 2391-52 has a serious reputation because it tests judgement: interpreting readings, coding defects and certifying, under observation and against the clock.
- 2.There are two assessments. An open-book, invigilated online multiple-choice test (2391-052) with a pass mark of approximately 75%, and a practical assignment (2391-502).
- 3.City & Guilds publishes no official pass rate. The scary figures you see on forums are anecdotes.
- 4.Prepared candidates pass it. The failures cluster around five predictable traps, and every one of them is fixable in training.
What the 2391-52 actually is
The full title is the City & Guilds Level 3 Award in Initial and Periodic Inspection and Testing of Electrical Installations (2391-52). It sits behind the two jobs that certify electrical work in the UK: initial verification of new installations, and periodic inspection of existing ones. That second job is the one behind every EICR.
To achieve the award you pass two separate City & Guilds assessments:
| Assessment | What it is | What makes it demanding |
|---|---|---|
| 2391-052 online test | Open-book, invigilated multiple-choice test. You can take BS 7671 and Guidance Note 3 in. | A pass mark around 75%, against the clock. Open book only helps if you can navigate the books at speed. |
| 2391-502 practical assignment | A practical assessment: inspecting, testing and completing the certification on a real installation. | You work the full sequence under observation, and the paperwork is marked as hard as the testing. |
Neither half is a memory test. Both ask the same underlying question. Can you inspect and test an installation you've never seen, work out what the instruments are telling you, and stand behind the certificate you sign?
So how hard is it really?
Harder than the 18th Edition. Most electricians who hold both will say so without hesitation. The 18th Edition exam asks whether you can find the right regulation; the 2391 asks whether you can apply it on an installation with faults you weren't warned about. Different muscle entirely.
Here’s the honest framing. The 2391 is a professional-judgement exam sat mostly by busy working electricians, many of whom last sat a formal exam years ago and revised less than they meant to. Prepared candidates pass. Under-prepared candidates fund the resit industry.
The five reasons people fail
Talk to assessors and trawl the forums and the same five traps come up again and again.
Treating open book as a safety net
The 2391-052 lets you bring BS 7671 and Guidance Note 3 in. Candidates hear “open book” and relax. But the pass mark is around 75% against the clock, and if you’re meeting Guidance Note 3’s layout for the first time in the exam, you’ll run out of time on questions you could have got right. The books are there to confirm what you already nearly know.
Knowing the test sequence but not the why
Continuity, insulation resistance, polarity, then the live tests. Most candidates can recite that order. The exam asks why the order exists, and what happens to your results when something upstream changes.
Misreading the readings
Conductor length, temperature, parallel paths, connected loads and lead nulling all skew real-world results. The exam is full of “this reading looks wrong, what’s going on?” questions. That’s deliberate, because it’s the actual job of an inspector.
Coding and paperwork
Deciding between a C1, C2, C3 and FI on an EICR is judgement work. And the certification paperwork in the practical is marked as strictly as the testing. An immaculate test sequence with a wrongly coded defect still fails.
Nerves in the practical
Working a full inspection under an assessor’s eye is a different experience from doing it alone in a customer’s garage. The fix is repetition. Enough supervised practice that the sequence runs on autopilot before assessment day.
Every one of the five is fixable in training. None of them is fixable on the morning of the exam.
Is it worth the effort?
In our view this is the easiest part to answer. Inspection and testing is where the demand, and the day rates, currently are.
Work the first two numbers through and England’s private rented sector alone implies somewhere near a million EICRs a year, before social housing joins the queue. A typical domestic EICR runs £100 to £350 depending on the property, per 2026 cost guides, for a few hours on site. Qualified inspectors are what that whole cycle runs on. There aren’t enough of them.
How to prepare properly
Preparation that actually works maps straight onto the five traps.
Learn the books as tools. Practise finding things in BS 7671 and Guidance Note 3 until navigation is fast and boring. Tab the sections you keep returning to. In an open-book exam, speed in the books is marks.
Reason the sequence, code real examples, practise the paperwork. Work through why each test precedes the next. Code worked defect examples until C2 versus C3 stops feeling like a coin toss. Fill in real certificates and schedules before the assessor is watching you do it.
Test yourself before City & Guilds does.Our course ends with a thirty-question practice test weighted across the four knowledge outcomes, and you can sit it as often as you like. It’s revision, not the real paper. That’s the point: find the gaps while they’re still free to fix.
You’ll need relevant installation experience or qualifications to start, typically the 18th Edition and an NVQ Level 3 or equivalent. From there, the theory is online at your own pace, the practical training runs at our Derby centre, and the £800 (+ VAT) price includes both City & Guilds assessment fees.
Not on the tools yet? Testing has a lower rung on the same ladder: our guide to whether PAT testing is a legal requirement explains the appliance-testing route, which needs no electrical background at all.
Your questions, answered
Do I need the 18th Edition before the 2391?
You need relevant electrical installation experience or qualifications. The 18th Edition plus an NVQ Level 3, or equivalent, is the usual starting point. The 2391 is aimed at working electricians moving into inspection, testing and certification, not at beginners.
Is the 2391 exam open book?
Yes. The online multiple-choice test (2391-052) is open book and invigilated, so you can take BS 7671 and Guidance Note 3 in with you. The pass mark is approximately 75%. Open book rewards knowing your way around the books quickly rather than looking everything up from scratch.
What is the difference between 2391-50, 2391-51 and 2391-52?
2391-50 covers initial verification only, 2391-51 covers periodic inspection only, and 2391-52 combines both in one award. Most people take the 2391-52 because employers and scheme bodies generally want both halves.
What is the 2391 pass rate?
City & Guilds doesn't publish one. Training providers commonly report first-time pass rates somewhere around 30 to 40%, but treat those as anecdote rather than data. What's beyond doubt is that unprepared candidates fail it regularly, and for predictable reasons.
Will the 2391 let me sign off EICRs?
Yes. The 2391 is the qualification behind periodic inspection and EICR work, alongside the right experience and, for some work, scheme registration.
How long does it take to prepare?
With our course the theory is online and self-paced, so that part is up to you. Most working electricians spread it over a few weeks around their jobs, then take the practical training and both City & Guilds assessments at our Derby centre. New assessment dates are being finalised now and will be announced soon.
Ready to get qualified?
Inspection & Testing: City & Guilds 2391-52: theory online at your own pace, assessment at our Derby centre.
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