EICR Codes Explained: C1, C2, C3 and FI

Your electrical inspection report has come back with codes — but what do they mean, and what do you actually need to do about them? Here's a clear explanation of every EICR observation code.

Why Do EICRs Use Codes?

Rather than simply passing or failing a property, an EICR grades each observation according to its severity. This gives you — and any remedial electrician — a clear picture of what needs immediate attention versus what can wait.

C1 — Danger Present

A C1 observation means there is a risk of injury or death. The electrician carrying out the EICR is required to make the installation safe before leaving the property — this might mean isolating a circuit, removing a fitting or applying a warning notice.

Common C1 observations: Exposed live conductors, missing earth connections on high-risk circuits, severely damaged accessories with exposed terminals.

What to do: The electrician should address C1 observations during the inspection. If they can't fix it immediately, you must not use the affected circuit until it's repaired.

C2 — Potentially Dangerous

A C2 observation means the fault is potentially dangerous but doesn't pose an immediate risk. C2 faults must be remedied within 28 days of the EICR being issued. Until they're fixed, the installation is not classified as satisfactory.

Common C2 observations: No RCD protection, missing main earth bonding, inadequate supplementary bonding in bathrooms, deteriorated cable insulation, overloaded circuits.

What to do: Book a qualified electrician to carry out electrical inspections once the work is complete.

C3 — Improvement Recommended

A C3 observation means an improvement is recommended but the installation is not considered dangerous as it stands. A C3 alone does not prevent the EICR from being classified as satisfactory.

Common C3 observations: Old-style consumer unit without RCDs (where there are no C2 issues), older wiring that is serviceable but ageing, sockets without child-resistant shutters.

What to do: C3 items should be addressed in time, but there's no legal deadline. If your electrical inspection has only C3 observations it will be issued as satisfactory.

FI — Further Investigation Required

An FI means the electrician couldn't fully assess something during the inspection — perhaps because of limited access, concealed wiring or an intermittent fault. Further investigation is required before the EICR can be finalised.

What to do: Arrange the further investigation as soon as possible. The electrician will advise on what's needed — it might be opening up a ceiling, testing a specific circuit or tracing a concealed cable run.

Satisfactory vs Unsatisfactory

An EICR is issued as Satisfactory if there are no C1, C2 or FI observations (C3 items are allowed). It's issued as Unsatisfactory if any C1, C2 or FI observations are present. For landlords, an unsatisfactory EICR means remedial works must be completed and evidence provided to tenants within 28 days.