What is a C1 code on an EICR?

C1 is the code people most need to understand, because it signals a live danger. The sections below explain what triggers it, what happens on the day, and what you must do.

What 'danger present' means

The classification codes on an EICR rank how serious each issue is. C1 sits at the top: it means a danger is present and active, with a real and immediate risk of injury to someone using the installation. The wording on the model report is "Danger present. Risk of injury. Immediate remedial action required."

This is different from a C2, which is potentially dangerous — a fault that could become dangerous under certain conditions. A C1 is dangerous as things stand. That distinction matters because it changes the urgency: a C1 is not something to schedule for next month.

The word "present" is doing the work in that phrase. A C1 does not describe a fault that might cause harm if several things go wrong at once; it describes a hazard that is live and accessible as the installation stands, so that an ordinary action — touching a fitting, plugging something in, brushing past an accessory — could result in a shock, burn or fire. That is the line between C1 and C2: a C2 needs a further fault or an unlucky combination of events to become dangerous, whereas a C1 is already there. Because the danger is current rather than hypothetical, a C1 is the one code where the timing of the response is not a matter of judgement or convenience. It is also why inspectors are trained to act on a C1 the moment they find one, rather than completing the rest of the inspection first and dealing with it at the end.

Examples of C1 faults

C1 codes are given to conditions where someone could come into contact with live electricity or where a fire risk is immediate. Typical examples include:

• Exposed live conductors — bare wires that can be touched.
• A missing or broken socket or switch faceplate exposing live terminals.
• Incorrect polarity resulting in a metal part or appliance casing being live.
• Damaged accessories with accessible live parts.
• An unsafe connection that is overheating or arcing.

The common thread is accessible live parts or an immediate shock or fire hazard. These are the conditions that put a household at risk today, which is why they are treated with the most urgency.

What unites these examples is not the type of component involved but the fact that the danger requires no further failure to cause harm. With an exposed conductor or a live casing, the hazard is already complete: an ordinary touch is all it takes. That is the test an inspector is applying when they reach for a C1 rather than a C2 — they are asking whether someone could be hurt by the installation as it is, not by the installation plus an additional fault. It also explains why C1 faults are comparatively rare on a typical domestic report: most defects in a home that has been wired and used normally are degradations of protection (C2 territory) rather than openly live parts. When a C1 does appear, it usually points to damage, interference or a botched alteration that has left something exposed, which is exactly why it cannot wait. That origin is also a clue worth noting: because C1 faults so often follow interference rather than ordinary ageing, finding one is a reason to look carefully at whatever recent work or damage produced it.

What happens when a C1 is found

Because a C1 is an immediate danger, electricians do not simply note it and move on. With the occupier's agreement, the electrician will normally make the danger safe on the day — for example by isolating the affected circuit or removing the hazard — and record both the fault and the action taken. Making it safe is not the same as fixing it: the underlying defect still needs proper remedial work.

For the report itself, any C1 makes the overall result unsatisfactory, alongside C2 and FI codes. The remedial work should be carried out as soon as possible and confirmed in writing. For privately rented homes in England, where the 2020 Electrical Safety Standards Regulations apply, the landlord must complete remedial work within 28 days of the inspection or sooner where the report requires it — and a C1 will typically demand action well inside that window because of the immediate risk. Keep the confirmation that the work has been done with your records.

How C1 sits alongside the other codes

To understand a C1 fully it helps to see where it sits in the full set of classification codes used on the model EICR form. Each observation the electrician records is given one code, and the codes are about severity and urgency, not about which part of the installation is affected.

• C1 — danger present: immediate risk of injury, action required at once. Makes the report unsatisfactory.
• C2 — potentially dangerous: not hazardous as things stand, but could become dangerous under fault conditions. Urgent remedial action. Also makes the report unsatisfactory.
• C3 — improvement recommended: not a danger, just below the current standard. Does not, on its own, make the report unsatisfactory.
• FI — further investigation: the inspector found something that needs investigating before it can be coded properly. Makes the report unsatisfactory until resolved.

A single report can carry a mix of these. What matters for the C1 specifically is that it never waits its turn: even if a report is otherwise full of harmless C3 items, one C1 makes the result unsatisfactory and triggers immediate action. This is also why you should read the actual coded observations rather than just the overall result — the word "unsatisfactory" alone does not tell you whether you are dealing with one urgent C1 or a handful of minor points.

Frequently asked questions

Sources & further reading

• Electrical Safety First — EICR codes explained
• NICEIC — understanding EICR classification codes

Figures on this page are typical UK ranges drawn from published sources and depend on your specific property. They are guidance, not a quotation. Legal duties are summarised for guidance — confirm the current position on GOV.UK.