Understanding EICR Codes (C1, C2, C3, FI)

• C1 means danger is present and needs immediate action.

• C2 means potential danger and needs urgent action.

• C3 means improvement recommended (it’s not automatically a fail).

• FI means further investigation required without delay.

We’re electricians at Azure Electrical and we carry out electrical inspection and testing across London and surrounding areas (and wider UK sites). When an EICR lands on a desk, the first thing most caretakers, site managers, local authority teams and employers do is scan for the codes.

That makes sense. The codes tell you what needs doing now, what can be planned and what needs a closer look.

What are EICR codes used for?

EICR codes are a way for the inspector to record observations by urgency. The IET (BS 7671 guidance) is clear that observations found during inspection and testing must be recorded and coded according to how urgent they are.

Good reporting should also be written so the person ordering the work can understand it, avoiding unnecessary technical language.

The four codes you’ll see most often

C1: Danger present (immediate action required)

What it means: There is an immediate risk of injury.
What happens next: You may need to isolate a circuit or area until the danger is removed. The NICEIC best practice guide explains that where C1 is appropriate, the client should be advised immediately and in writing that immediate remedial action is required (or has been taken).

Typical site-manager reality:
C1 is the “stop and make safe” category. On a school site, that’s exactly the moment you’ll want clear communication, quick isolation (if needed) and a record of what was done.

C2: Potentially dangerous (urgent action required)

What it means: It might not be dangerous at that exact moment, but it could become dangerous if a fault occurs or conditions change.
What happens next: The NICEIC best practice guide describes C2 as requiring urgent remedial action.

Typical site-manager reality:
C2 is often where schools sit after an inspection. The building can usually keep operating, but the issue needs scheduling quickly and sensibly, ideally in a way that limits disruption (after hours, inset days or in holiday blocks).

C3: Improvement recommended (plan it)

What it means: Not unsafe, but improvement would enhance safety.
Does C3 fail an EICR? Not necessarily. GOV.UK guidance explains that C3 is an improvement recommendation and further remedial work is not required for the report to be deemed satisfactory.

Typical site-manager reality:
C3 items are perfect for planned maintenance, refurbishment weeks or when you’re already upgrading lighting or adding power. They’re often the difference between “bare minimum” compliance and a site that’s robust and future-ready.

FI: Further investigation required (without delay)

What it means: More investigation is needed before safety can be confirmed. Both the IET and NICEIC guidance describe FI as requiring further investigation without delay.
The NICEIC best practice guide also notes that if an observation can’t be coded due to reasonable doubt about danger/potential danger, the outcome must be reported as unsatisfactory.

Typical site-manager reality:
FI can feel frustrating because it isn’t a neat “fix this part” instruction. The quickest way to reduce stress is to treat FI as a short, focused investigation task with a clear scope, then make a decision based on what’s found.