About the exam
City & Guilds 2391 Exam structure
An independent route-aware study guide for City & Guilds 2391-50 initial verification, 2391-51 periodic inspection and 2391-52 combined inspection and testing, with current assessment structures and the practical competence boundary kept explicit.
Issuer and path
City & Guilds 2391 Inspection and Testing Study Guide is administered through City & Guilds. Check official resources before booking, retesting, or relying on a stale requirement.
Routes, Requirements and Current Sources
0 scored + 0 pretest
Choose 2391-50, 51 or 52, separate initial verification from periodic condition reporting and control the assessment-document edition. The 76-item allocation is Pass Harbor planning, not an official route weighting.
Safety Management and Instrument Control
0 scored + 0 pretest
Plan safe work, isolate correctly and control instruments, leads, PPE, people and premises. The 75-item allocation is Pass Harbor planning, not an official route weighting.
Initial Verification and Inspection
0 scored + 0 pretest
Prepare information, inspect new work before testing and manage unsatisfactory findings and certification responsibilities. The 75-item allocation is Pass Harbor planning, not an official route weighting.
Periodic Inspection and Classification
0 scored + 0 pretest
Agree extent, limitations and sampling, inspect existing installations and classify observations proportionately. The 75-item allocation is Pass Harbor planning, not an official route weighting.
Dead Testing and Continuity
0 scored + 0 pretest
Prepare, sequence and interpret continuity, insulation-resistance, polarity and earth-electrode evidence. The 100-item allocation is Pass Harbor planning, not an official route weighting.
Live Testing, Function and Results
0 scored + 0 pretest
Control live-test risk and interpret loop impedance, fault current, RCD, phase-sequence, functional and voltage-drop evidence. The 100-item allocation is Pass Harbor planning, not an official route weighting.
Documentation and Integrated Application
0 scored + 0 pretest
Complete the correct certificate or report, explain results and limitations and keep written preparation within the practical-assessment boundary. The 100-item allocation is Pass Harbor planning, not an official route weighting.
Confirm the exact route and document version with the centre
Ask for the qualification number, E-volve code, practical assignment code, live Amendment version, permitted references and any centre book-inspection rules before booking.
Official Outline Coverage Map
Coverage is mapped to official outline item counts so content depth can be checked without hard-coding a single exam.
| Topic | Official outline items | Your questions | Your flashcards | Confidence |
|---|---|---|---|---|
| Current routes, entry expectations and assessment pairs | 0 | 26 | 5 | Good |
| Purpose and distinction of initial verification and periodic inspection | 0 | 25 | 5 | Good |
| Statutory, non-statutory, regional and edition control | 0 | 25 | 5 | Priority |
| Safety management, safe isolation and affected persons | 0 | 50 | 10 | Priority |
| Instrument characteristics, test methods and influencing factors | 0 | 200 | 40 | Priority |
| Information, documents and responsibility for initial verification | 0 | 25 | 5 | Good |
| Initial inspection before testing and unsatisfactory new work | 0 | 50 | 10 | Priority |
| Purpose, extent, limitations and sampling for periodic inspection | 0 | 25 | 5 | Priority |
| Periodic inspection of an existing installation | 0 | 25 | 5 | Priority |
| Result interpretation, compliance and periodic classification | 0 | 75 | 15 | Priority |
| Initial certification and periodic condition reporting | 0 | 50 | 10 | Good |
| Route-specific practical assignment and permitted-reference boundary | 0 | 25 | 5 | Priority |
How to use this guide
Prepare from agreed scope to defensible handover
Start with route and purpose, control safety and source edition, gather inspection evidence, test methodically and complete the correct certificate or condition report.
V — Verify route and purpose
Identify new-work verification, existing-installation condition reporting or the combined path and its current assessment documents.
E — Establish scope and safety
Gather information, agree extent and limitations where relevant, assess risk and control isolation, people and systems.
R — Review by inspection
Use the applicable schedule and safe sensory evidence before deciding which tests are necessary and safe.
I — Instrument and test correctly
Select a suitable instrument, follow the justified sequence or periodic adaptation and record valid results.
F — Form a finding
Account for influencing factors and decide compliance, unsatisfactory new work or periodic classification from the evidence.
Y — Yield the right document
Complete the certificate or condition report, schedules, limitations, observations and handover consistently.
Route first
Separate verification from condition reporting
The same installation evidence can support different decisions and documents depending on whether the work is initial or periodic.
Qualification Route and Entry
Match prior learning and intended work to the correct current qualification and assessment pair.
Choose a topic to open below
Purpose, Law and Publications
Distinguish new-work verification, existing-installation reporting and current source control across UK nations.
Choose a topic to open below
Evidence to decision
Interpret before certifying or coding
Validate the method and influencing factors before turning a displayed value into a compliance or classification decision.
What to memorize cold
Interpret Results, Factors, Compliance and Classification: purpose
Turn measurements into decisions after accounting for method, instrument, circuit length, temperature, loading and parallel paths.
Interpret Results, Factors, Compliance and Classification: method
Validate the test setup, identify influencing factors, compare with the applicable criterion and cross-check against inspection and other results.
Interpret Results, Factors, Compliance and Classification: key fact 1
The same displayed number can require different interpretation at initial verification and periodic inspection.
Interpret Results, Factors, Compliance and Classification: key fact 2
The public ranges name circuit length, temperature, parallel conductors, loading and preparation or nulling as result factors.
Interpret Results, Factors, Compliance and Classification: boundary
A pass/fail display cannot replace professional interpretation of method validity and installation context.
Best next move
Validate the method and influencing factors before turning a displayed value into a compliance or classification decision.
Choose 2391-50, 2391-51 or 2391-52
Match initial verification, periodic condition reporting or the combined path to prior learning and intended work.
Key rules
Rule 1
Match initial verification, periodic condition reporting or the combined path to prior learning and intended work.
Exam cue: Confirm the qualification number, unit, E-volve assessment and practical assignment before planning study.
Rule 2
2391-50 pairs unit 500 with 050 and 500; 2391-51 pairs 501 with 051 and 501; 2391-52 pairs 502 with 052 and 502.
Exam cue: State whether the decision belongs to initial verification, periodic inspection or both before applying it.
Rule 3
The suite is CPD for experienced electrotechnical workers, not a route for a person new to the industry.
Exam cue: Name the route, purpose, safety control, evidence and final document before choosing an action.
Rule 4
The centre decides entry suitability after assessing qualification, experience and the ability to work safely.
Exam cue: Name the route, purpose, safety control, evidence and final document before choosing an action.
Study it this way
Purpose
Know what the evidence must establish
Match initial verification, periodic condition reporting or the combined path to prior learning and intended work.
Method
Use a safe repeatable sequence
Confirm the qualification number, unit, E-volve assessment and practical assignment before planning study.
Boundary
Keep route and practical limits visible
The centre decides entry suitability after assessing qualification, experience and the ability to work safely. Do not choose the periodic-only path merely because its online test is shorter; it assumes an initial-verification foundation.
Common traps
Do not choose the periodic-only path merely because its online test is shorter; it assumes an initial-verification foundation.
Prevention: Confirm the current source and stop when evidence, competence or task authority is insufficient.
Do not substitute a memorised sequence or displayed value for safe evidence and professional judgement.
Prevention: Confirm the current source and stop when evidence, competence or task authority is insufficient.
Memory anchors
Choose 2391-50, 2391-51 or 2391-52: purpose
Match initial verification, periodic condition reporting or the combined path to prior learning and intended work.
Choose 2391-50, 2391-51 or 2391-52: method
Confirm the qualification number, unit, E-volve assessment and practical assignment before planning study.
Choose 2391-50, 2391-51 or 2391-52: key fact 1
2391-50 pairs unit 500 with 050 and 500; 2391-51 pairs 501 with 051 and 501; 2391-52 pairs 502 with 052 and 502.
Choose 2391-50, 2391-51 or 2391-52: key fact 2
The suite is CPD for experienced electrotechnical workers, not a route for a person new to the industry.
Choose 2391-50, 2391-51 or 2391-52: boundary
The centre decides entry suitability after assessing qualification, experience and the ability to work safely.
Next best moves
Quick check-up
Use a short quiz to confirm the rule pattern is actually sticking.
Check-up Questions
Next step personalized recommendations
Open another topic next
Official resources
Verify the details with the official sources
Use these links for eligibility, scheduling, handbook rules, and issuer updates. Our guide helps you study; official sources tell you what the testing partner currently requires.
City & Guilds Initial and Periodic Inspection and Testing (2391)
Current three-pathway qualification page, assessment summary, availability, dates, qualification metadata and Amendment 4 transition notice.
City & Guilds 2391-50 handbook v2.3
Official initial-verification route, unit 500 outcomes, 050 test specification, entry expectations and practical-assignment requirement.
City & Guilds 2391-51 handbook v2.4
Official periodic-inspection route, unit 501 outcomes, 051 test specification, condition classifications and reporting scope.
City & Guilds 2391-52 handbook v2.4
Official combined route, unit 502 outcomes and 052 test specification, including the published outcome-table anomalies noted in this guide.
City & Guilds permitted reference materials v3.1
May 2026 guide confirming route-specific online, visual, practical and short-answer times and reference-material rules.
IET BS 7671:2018+A4:2026 Orange Book
Official current consolidated Eighteenth Edition Amendment 4 publication for current professional practice.
IET On-Site Guide, ninth edition
Official 2026 On-Site Guide aligned to BS 7671:2018+A4:2026 and named as a permitted 2391 reference.
IET Guidance Note 3, tenth edition
Official 2026 inspection-and-testing guidance updated to BS 7671:2018+A4:2026.
IET BS 7671 edition checker
Official current-edition, transition and errata page, including the separate Brown Book transition and Guidance Note 3 errata.
HSE GS38 electrical test equipment guidance
Official HSE guidance on suitable electrical test equipment, leads and precautions for electricians.
FAQ
Common City & Guilds 2391 questions
What is the difference between 2391-50, 2391-51 and 2391-52?
2391-50 covers initial verification of new work. 2391-51 adds periodic inspection, testing and condition reporting for someone who already has an initial-verification foundation. 2391-52 combines both for an experienced electrician who needs both skill sets together or wants to update and reaffirm them.
What are the three online test structures?
2391-050 and 2391-051 each contain 40 questions in 90 minutes. 2391-052 contains 60 questions in 120 minutes. All are open-book, invigilated E-volve multiple-choice tests graded Pass/Fail.
How are 2391-050 questions distributed?
The initial-verification handbook assigns outcomes 1–4 counts of 3, 3, 7 and 27, reported as 7%, 7%, 18% and 68%. Outcome 5 is practical performance and has no online questions.
How are 2391-051 questions distributed?
The periodic handbook assigns outcomes 1–4 counts of 5, 2, 7 and 26, reported as 13%, 5%, 17% and 65%. Outcome 5 is practical performance and has no online questions.
How are 2391-052 questions distributed?
The combined handbook prints counts of 13, 3, 11 and 33 with weights of 22%, 3%, 19% and 56%. The printed safety row is internally inconsistent because 3 of 60 is 5%, but this guide preserves the official table instead of silently changing it.
What is the pass mark?
Each handbook says approximately 75%, but also says City & Guilds may adjust the boundary to support consistency across cohorts. It is therefore not a guaranteed fixed raw score.
What is in the practical assignment for 2391-50?
The current permitted-materials guide lists a 150-minute practical Task A and a 60-minute short-answer Task B. The practical permits the three core references only for confirming test results; the short-answer task permits them generally.
What is in the practical assignment for 2391-51?
The guide lists a 30-minute no-reference visual-inspection Task A, a 150-minute practical Task B with references only for confirming results, and a 60-minute open-reference short-answer Task C.
What is in the practical assignment for 2391-52?
The guide lists a 30-minute no-reference visual-inspection Task A, a 150-minute practical Task B with references only for confirming results, and an 80-minute open-reference short-answer Task C.
Which books are permitted?
For 050, 051 and 052, the current guide permits BS 7671, the IET On-Site Guide and IET Guidance Note 3. Task-specific restrictions differ, and the centre's current instructions control the assessment.
Are the assessments already fully aligned to Amendment 4?
City & Guilds says relevant written and practical tasks will be amended to Amendment 4 within qualification documentation in due course. The April handbooks update a documentation range, but the public page does not confirm that every live task has completed the transition. Ask the centre to confirm the current version and permitted books.
Why does this guide identify combined unit 502?
The 2391-52 structure statement, assessment numbers and unit chapter consistently identify 502. One summary table in the handbook prints 501 once; this guide treats that isolated entry as a source typo and records the boundary explicitly.
What is the difference between an EIC and an EICR?
An Electrical Installation Certificate records initial verification of applicable new work and responsible declarations. An Electrical Installation Condition Report records the condition of an existing installation within stated extent and limitations, including observations and classifications.
Can this guide replace practical training?
No. It supports underpinning knowledge and decision sequence, but it cannot demonstrate safe isolation, visual inspection, instrument handling, test performance or completion of a controlled assignment.
Does the planned 601-item allocation reproduce one official exam?
No. It is a cross-route Pass Harbor study allocation. The official 050, 051 and 052 tests are alternative assessments with different lengths and distributions, and each route also has a practical assignment.