Guide to City & Guilds 2391 Inspection & Testing
Everything you need to know about the 2391-52 qualification — what it covers, who needs it, and how it unlocks self-employment, scheme registration, and higher earnings.
What Is the 2391-52 Inspection & Testing Qualification?
The City & Guilds 2391-52 is the industry-standard qualification for electrical inspection and testing in the UK. It proves that you can carry out both initial verification of new electrical installations and periodic inspection of existing installations, in accordance with BS 7671 (the 18th Edition Wiring Regulations).
Without the 2391, you cannot legally sign off Electrical Installation Certificates (EICs) or produce Electrical Installation Condition Reports (EICRs). This makes it an essential qualification for anyone who wants to work as a self-employed electrician, register with NICEIC or NAPIT, or carry out inspection work.
It is one of the five qualifications required for the adult diploma route to becoming a fully qualified electrician with a JIB Gold Card.
What You Will Learn
The 2391-52 covers two main areas of competence
Initial Verification
Testing and certifying new electrical installations before they are put into service.
- Safe isolation procedures
- Continuity testing (R1+R2, ring final circuit)
- Insulation resistance testing
- Polarity verification
- Earth fault loop impedance (Zs)
- RCD testing (trip times and characteristics)
- Completing Electrical Installation Certificates
Periodic Inspection
Inspecting and testing existing installations to assess their condition and safety.
- Visual inspection of existing installations
- Sampling strategies for large installations
- Testing without disconnecting circuits
- Identifying defects and coding observations
- Limitation of inspection scope
- Producing Electrical Installation Condition Reports
- Recommending remedial actions (C1, C2, C3, FI codes)
Who Needs This Qualification?
Practising electricians who need to sign off their own work
Electricians seeking Part P Building Regulations self-certification
Those applying for NICEIC or NAPIT registration as an approved contractor
Qualified electricians looking to progress into inspection roles
Electricians wanting to carry out periodic inspections for landlords and businesses
Those completing the adult diploma route and need the 2391 for their JIB Gold Card
Course Structure
Our 2391-52 course combines classroom theory with practical workshop sessions. You will learn the testing procedures, practise on real circuits, and prepare for both the online exam and practical assessment.
Classroom Theory
BS 7671 requirements, testing sequences, documentation, and calculation methods
Practical Workshops
Hands-on testing with industry-standard equipment on real circuits and installations
Assessment
Online multiple-choice exam plus a practical assessment on a real installation
Prerequisites
Before enrolling on the 2391-52, you should have:
18th Edition Wiring Regulations (BS 7671)
A current 18th Edition qualification is mandatory. The 2391 is entirely based on the requirements of BS 7671.
Level 3 qualification or equivalent experience
You should have a Level 3 Diploma in Electrical Installations (2365) or equivalent on-the-job experience. Some candidates with extensive practical experience may be eligible without formal Level 3.
Competent maths skills
You will need to perform electrical calculations including Ohm's law, power calculations, voltage drop, and fault current calculations.
What the 2391 Unlocks
Self-Employment
The 2391 is essential for self-employed electricians. You cannot sign off Electrical Installation Certificates (EICs) or Electrical Installation Condition Reports (EICRs) without it.
NICEIC / NAPIT Registration
To become an approved contractor with NICEIC, NAPIT, or other Part P scheme providers, you need the 2391 qualification. This allows you to self-certify your work under Building Regulations.
Part P Self-Certification
With the 2391 and scheme membership, you can self-certify notifiable electrical work without needing to involve building control — saving your customers time and money.
Higher Earning Potential
Electricians with the 2391 command higher rates because they can take on inspection work, sign off installations, and operate independently. Periodic inspection work alone is a lucrative income stream.
Ready to Get Your 2391?
View our 2391-52 Inspection & Testing course page for current dates, pricing, and available payment plans. Small class sizes mean places fill quickly.
View Course & DatesFrequently Asked Questions
How difficult is the 2391 exam?
The 2391 is considered one of the more challenging electrical qualifications. It requires a solid understanding of BS 7671 (18th Edition) and the ability to apply it to real-world scenarios. The online exam tests your knowledge, while the practical assessment tests your hands-on testing skills and ability to complete documentation accurately. With proper preparation and training, the pass rate is good.
What happens if I fail the assessment?
If you fail either the online exam or the practical assessment, you can re-sit. There is an additional fee for re-sits. We provide support and guidance to help you prepare for any re-sit, and most candidates pass on their second attempt.
Do I need to renew the 2391 qualification?
The 2391 qualification itself does not expire. However, it is tied to a specific edition of BS 7671. When a new edition of the wiring regulations is released (the current 18th Edition was published in 2018), you will need to update your 18th Edition qualification but the 2391 remains valid.
Can I do the 2391 without the 18th Edition?
No. The 18th Edition Wiring Regulations (BS 7671) is a prerequisite for the 2391. The entire inspection and testing process is based on the requirements of BS 7671, so you need a current and thorough understanding of the regulations before attempting the 2391.
What is the difference between 2391-51 and 2391-52?
The 2391-51 covered initial verification only (new installations). The 2391-52 covers both initial verification AND periodic inspection and testing (existing installations). The 2391-52 is the current standard and is what employers and scheme providers require. We deliver the 2391-52.
How long is the course?
Our 2391-52 course typically runs over 5 days, combining classroom theory, practical workshop sessions, and assessment time. Check the course page for current dates and availability.
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