Free mock exam
EICR Coding Practice: C1, C2, C3 or FI?
Free practice at coding EICR observations. Each question is an observation written the way it would appear on a Condition Report, from a consumer unit with no RCD protection to scorching at a socket-outlet. Choose C1 (danger present), C2 (potentially dangerous), C3 (improvement recommended) or FI (further investigation), then read the typical coding and why. 20 questions are drawn from a bank of 76 real-world examples. Coding is always the inspector's judgement on the day, so treat these as the codings most inspectors would give, not the only defensible answer. Under the BS 7671:2018+A4:2026 model form only C1 and C2 make the report Unsatisfactory; C3 and FI are advisory.
- Questions
- 20
- Time limit
- 25 min
- Pass mark
- 70% · 14/20
- Question bank
- 76
Free, no sign-up. Retake as many times as you like — different questions each time.
Sample questions
01How would this observation typically be coded on an EICR? "Missing blanking plate on consumer unit leaving live busbar accessible to touch"
- AFI — Further investigation
- BC2 — Potentially dangerous
- CC1 — Danger present
- DC3 — Improvement recommended
Why: Typically C1. A gap in the consumer unit front leaves live parts accessible to a finger without using a tool. Anyone resetting a breaker could contact the live busbar, so most inspectors code this C1 — danger present, make safe before leaving site.
02How would this observation typically be coded on an EICR? "Plastic (thermoplastic) consumer unit installed under wooden staircase, enclosure in good condition"
- AC2 — Potentially dangerous
- BFI — Further investigation
- CC1 — Danger present
- DC3 — Improvement recommended
Why: Typically C3. Current standards call for consumer units in domestic premises to have a non-combustible (typically metal) enclosure, and a location under an escape route makes fire containment matter more. Where the plastic unit is undamaged with sound terminations, this is commonly coded C3 — an improvement recommendation, not an immediate danger.
03How would this observation typically be coded on an EICR? "Signs of thermal damage and discolouration at main switch terminal within consumer unit"
- AC2 — Potentially dangerous
- BFI — Further investigation
- CC1 — Danger present
- DC3 — Improvement recommended
Why: Typically C2. Heat damage at a main switch terminal points to a loose or high-resistance connection carrying the whole installation load, which can develop into a fire. Most inspectors code visible overheating at terminations C2 — potentially dangerous, urgent remedial action to remake the connection and replace damaged parts.
Common questions
Is the EICR Coding Practice: C1, C2, C3 or FI? mock exam free?
Yes — 100% free, no sign-up needed. Questions are pulled at random from a substantial bank, with a worked explanation on every question after you submit.
Can I retake the mock exam?
Yes. Every attempt picks a different random selection and reshuffles the options, so each retake gives you genuinely new questions. No limit on retakes.
Does this count towards the real qualification?
No — this is independent practice material. To gain the actual qualification you need to sit the official assessment through an approved provider.
What are examples of C1, C2 and C3 codes on an EICR?
Typical C1 (danger present): live parts that can be touched, such as a socket-outlet with a cracked faceplate exposing live terminals. Typical C2 (potentially dangerous): no RCD protection for socket-outlets that may supply equipment outdoors, or missing main protective bonding. Typical C3 (improvement recommended): a plastic consumer unit in a dwelling installed before the non-combustible requirement. FI is used where safety cannot be confirmed without further investigation, such as a suspected borrowed neutral.
Which EICR codes make the report unsatisfactory?
C1 and C2 only. Under the BS 7671:2018+A4:2026 model Condition Report, C3 and FI observations are advisory and do not affect the overall assessment, although some scheme providers still treat FI as unsatisfactory. Follow your scheme where its rules differ.