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Understanding EICR Codes: C1, C2, C3 and FI Explained
By Andrew Pearce · 27 Dec 2025 · 11 min read

Understanding EICR Codes: C1, C2, C3 and FI Explained

An Electrical Installation Condition Report (EICR) doesn't simply say "pass" or "fail". Instead, it lists individual observations against the wiring found in a property, and each observation is given a code that shows how serious it is. Once you understand what each EICR code means, the report stops being a list of jargon and starts being a clear, practical record of what your property needs.

This guide covers every code used in an EICR — C1, C2, C3, FI and LIM — what each one means in practice, how they affect the overall result, and what happens next if your report comes back unsatisfactory.

Why EICRs Use a Coding System

Every EICR is carried out against BS 7671, the UK wiring regulations. As an electrician works through a property, they test each circuit and log any observation that doesn't meet the current standard. Rather than describing severity in free text, the report uses a standardised code, so any electrician, landlord, letting agent or lender reading it understands the same thing.

This matters because an EICR is often read by people who aren't electricians. A landlord, a mortgage valuer or a letting agent needs to know at a glance whether an issue is urgent or cosmetic, without having to interpret technical description. The coding system does that job.

The EICR Codes at a Glance

CodeMeaningAction Required
C1Danger present — risk of injury right nowMake safe immediately
C2Potentially dangerous — no immediate risk, but could become oneRemedial work required
C3Improvement recommended — doesn't meet current regulations but isn't unsafeRecommended, not required
FIFurther investigation — couldn't be fully assessed on the dayFollow-up inspection needed
LIMLimitation — an area agreed to be outside the scope of the inspectionArrange access for a follow-up visit

C1 – Danger Present

A C1 is the most serious code an EICR can carry. It means the electrician found a risk of injury that exists right now, not one that might develop later. Exposed live conductors within reach, or a metal fitting that's live due to a wiring fault, are typical examples. Because the danger is immediate, it should be made safe on the spot, often before the report is even finalised.

Electrician using a multimeter to test a consumer unit during an EICR
Each observation during an EICR is tested and coded by severity.

C2 – Potentially Dangerous

A C2 means the observation isn't causing harm today, but leaves no protection if a fault occurs. A missing earth connection to exposed metalwork is a common example — nothing is wrong until the metalwork becomes live, at which point the missing earth means there's no safe path for the fault current. A C2 doesn't require the same immediate action as a C1, but it does require remedial work before the installation can be considered satisfactory.

C3 – Improvement Recommended

A C3 flags something that doesn't meet the current edition of the wiring regulations but wasn't unsafe when it was installed, and isn't a safety risk now. Older wiring colours, or an accessory that predates a later amendment to BS 7671, are typical C3s. A C3 is a recommendation, not a requirement — the report is still recorded as satisfactory overall even with C3s listed.

FI – Further Investigation

FI is used when the electrician couldn't safely or fully assess something during the visit — for example a circuit that couldn't be isolated because it was in use, or an area that needed specialist testing outside the scope of the inspection. An FI item isn't coded as a fault; it means a closer look is needed before it can be given a code at all.

Limitations (LIM) Explained

Separate from the C1–C3 and FI codes, a report can also record a Limitation. This is an agreed area the inspection didn't cover on the day — a locked outbuilding, a circuit the occupier asked not to be isolated, or underfloor wiring that wasn't accessible. A limitation isn't a fault; it's a record of what wasn't assessed, and it's usually resolved by arranging access for a follow-up visit.

What Makes a Report Unsatisfactory

The overall result of an EICR comes down to a simple rule, set out below.

Codes PresentOverall Result
C1 and/or C2Unsatisfactory
C3 only (no C1/C2)Satisfactory, with recommendations noted
No codesSatisfactory

An unsatisfactory result doesn't mean the whole installation is unsafe to use day to day — it means specific items need remedial work before the report can be reissued as satisfactory.

Electrician using a multimeter to test continuity at a consumer unit
Test results are what determine whether an observation is coded C1, C2, C3 or FI.

Common Examples of Each Code

Seeing real examples side by side makes it easier to understand why two properties with similar-looking faults can receive different codes — severity depends on the specific risk, not just the type of fault.

CodeTypical Example
C1Exposed live conductors within reach
C2Missing earth connection to exposed metalwork
C3Older accessory that predates current wiring colour standards
FICircuit that couldn't be safely isolated for testing on the day
LIMLocked outbuilding not accessible during the inspection

For how coded observations feed into pricing, see our guide to EICR costs in London.

What Happens After an Unsatisfactory EICR

An unsatisfactory result isn't the end of the process — it's the starting point for remedial work. We explain what each code on your report means for the property, then quote for the work needed to resolve any C1 and C2 items. Once that work is complete, the installation can be re-tested and the report reissued as satisfactory.

Why Codes Matter for Landlords and Buyers

A mortgage lender, letting agent or buyer's solicitor will often ask to see the EICR itself, not just a pass/fail summary. Understanding what each code means lets you read the report the way they will, and explain — if asked — what's already been resolved versus what's still outstanding.

For landlords specifically, an unsatisfactory EICR with unresolved C1 or C2 items can affect a property's compliance status. Our guides to landlord electrical safety certificates and HMO electrical safety cover the wider legal requirements this sits within.

How Often You'll See These Codes

Codes only appear when an EICR is carried out, and the frequency of testing depends on the type of property. Our guide on how often you need an EICR sets out the recommended intervals for owner-occupied homes, rented properties and commercial premises.

What an EICR Inspection Actually Involves

Before any code is assigned, the electrician carries out a structured set of checks against the installation. This typically includes a visual inspection of the consumer unit, accessories and visible wiring, followed by dead testing (with the power off) and live testing (with the power on) of individual circuits. Each circuit is checked for correct earthing, insulation resistance, polarity and the operation of protective devices such as RCDs and circuit breakers.

Every result is compared against the current edition of BS 7671. Where a circuit or accessory doesn't meet that standard, the electrician records what was found and assigns the appropriate code. This is why two properties of a similar age can receive very different reports — the codes reflect what's actually found on the day, not the age of the property alone.

Reading the Report Beyond the Codes

The codes sit alongside a written observation for each item, plus a reference to the specific circuit or location affected. A typical line in the schedule might read: "Socket outlet in kitchen — no earth connection detected — C2". Reading the description together with the code gives the full picture: what was found, where, and how serious it is.

The report also includes an overall summary page, which states whether the installation is satisfactory or unsatisfactory and lists the total number of C1, C2, C3 and FI observations. This summary page is usually what gets shared with a letting agent or mortgage lender, while the detailed schedule is what an electrician uses to price and carry out remedial work.

Report SectionWhat It Contains
Summary pageOverall result and total count of each code
Schedule of inspectionsChecklist of what was tested against BS 7671
Schedule of test resultsMeasured values for each circuit tested
Observations and recommendationsEach coded item, with description and location

Getting Coded Items Resolved

Once you have your report, the next step is straightforward: any C1 items get made safe first, then C2 items are quoted and scheduled as remedial work. C3 items can be actioned at the same time for convenience, or left for a later date since they aren't required. FI items need a follow-up visit to complete testing, and LIM items need access arranging before they can be assessed at all.

We can quote for and carry out the remedial work needed to resolve any coded observations from your report, and re-test the affected circuits once the work is done so the EICR can be reissued as satisfactory.

Typical Timelines for Remedial Work

How quickly coded items get resolved depends on the code and the scale of the work involved. A single C1, such as an exposed live conductor, is usually made safe on the same visit — often within the hour, before the electrician leaves the property. A C2 involving one circuit, like a missing earth connection at a socket, typically takes a single follow-up visit once parts are confirmed. Where C2s are widespread across a property, for example an older installation with several earthing issues, the work may need scheduling over one or two visits.

CodeTypical Timeline
C1Made safe same-day, often within the visit
C2Single follow-up visit for isolated items; longer if widespread
C3Actioned at a convenient time, no fixed deadline
FIFollow-up visit to complete the outstanding test

Once remedial work is complete, the affected circuits are re-tested and the report is updated to reflect the new result. For a property with only C3 recommendations, there's no obligation to act by a set date, though addressing them at the same time as other work is usually more cost-effective than a separate call-out later.

Who Can Carry Out an EICR

An EICR must be carried out by a qualified and competent electrician, typically someone registered with a recognised body such as NICEIC or NAPIT. This matters for two reasons: the inspection itself involves live testing that carries real risk if done incorrectly, and the codes assigned need to be applied consistently against BS 7671 for the report to be accepted by landlords, lenders and local authorities. A report from an unregistered or unqualified individual may not be accepted as valid evidence of compliance, even if the codes look correct on paper.

An EICR is often carried out alongside other compliance checks — see our guide to PAT testing for how portable appliance testing fits alongside the fixed installation checks covered here.

Frequently Asked Questions

Can I still rent out a property with a C3 code?

Yes. A C3 is a recommendation, not a requirement — the report is still recorded as satisfactory overall.

How quickly must a C1 be fixed?

A C1 indicates immediate danger and should be made safe as soon as possible, ideally before the report is even finalised.

Does an unsatisfactory EICR fail automatically?

Any C1 or C2 observation makes the report unsatisfactory. It doesn't mean the whole installation is unsafe to use — it means specific items need remedial work.

Can the same electrician who found the fault fix it?

Yes — we can quote for and carry out the remedial work needed to resolve any coded observations from your report.

For official guidance, see the government’s electrical safety standards guidance.

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