EICR C1, C2, C3 and FI Codes Explained: What Each Finding Means

EICR classification codes at a glance

The four codes are not grades on a scale from good to bad. C1 and C2 identify danger or potential danger. C3 records a recommended improvement. FI identifies a matter that the inspector could not establish within the inspection’s extent and limitations and advises further investigation. Each observation should describe the actual condition; the code is the inspector’s professional judgement about that condition, not an automatic label attached to the age of the installation.

• C1, danger present: immediate risk of injury; urgent action to remove the danger, often including safe isolation by a competent person.
• C2, potentially dangerous: urgent remedial action is required before a foreseeable fault or event makes the condition immediately dangerous.
• C3, improvement recommended: an upgrade may enhance safety, but the observation is not classed as immediate or potential danger.
• FI, further investigation advised: more evidence is needed to reach a proper conclusion; under the current A4 model form, FI alone does not change the overall result to unsatisfactory.

These descriptions follow Electrical Safety First Best Practice Guide 4, Issue 7.4 and the IET BS 7671:2018+A4:2026 model EICR form, both listed in the official sources below. The examples that follow illustrate how the reasoning works; they are not a substitute for an inspector assessing a real circuit.

The code belongs to the inspector who signs the report. Ask for the technical reasoning rather than a different code.

C1: danger is present now

A C1 observation means a person may be injured by the condition as it exists at the time of inspection. It is not a prediction that a failure might happen months from now. Exposed live parts that an ordinary person could touch are a straightforward example: a badly broken accessory or a consumer unit opening that exposes energised conductors may present a direct shock risk. Where practicable, the inspector should arrange or take appropriate action to make the danger safe and tell the person responsible immediately, rather than waiting for the final report.

Making a condition safe and completing the permanent repair may be separate tasks. A competent electrician may need to isolate an affected circuit or prevent access until a suitable repair can be completed. The fact that the rest of a house still has power does not make the C1 observation less serious. Occupants should not remove covers or attempt to confirm whether metalwork or wiring is live.

For a rented home in England, current GOV.UK guidance still expects FI findings to be investigated, so record the result in writing.

C2: potentially dangerous, even if nothing has failed yet

C2 is easy to underestimate because lights may still work and nobody may have noticed a fault. It identifies a condition that could become an immediate danger if a further fault or reasonably foreseeable event occurs. The lack of an effective protective conductor for equipment that depends on earthing, for example, can create a serious electric-shock risk if insulation subsequently fails. The exact classification depends on what is connected, what has been verified and the installation’s arrangements.

C2 calls for urgent remedial action, but the code does not by itself prescribe a specific product or a complete rewire. One property may need a targeted connection repair; another may need changes to its protective arrangements. The electrician should explain the defect, the risk it creates and what work will remove that risk. Owners should not try to keep equipment in use by repeatedly resetting a protective device or making their own alterations.

C3: improvement recommended is not the same as a dangerous defect

C3 describes something that can reasonably be improved for safety, without the inspector having identified immediate or potential danger from that particular observation. It is a recommendation rather than the same urgent instruction as C1 or C2. For instance, in an older installation a lack of additional RCD protection on a lighting circuit may be recorded as an improvement recommendation where the specific conditions justify that classification; a different circuit or environment may warrant a different judgement.

This is why an EICR is not simply a checklist against the newest product brochure. An installation built to an earlier edition of the Wiring Regulations will not necessarily require wholesale upgrading just because the standards have evolved. On the other hand, calling something C3 is not a licence to ignore deterioration or another independent source of danger. The evidence, the condition and the inspector’s reasoning remain decisive.

A report containing only C3 recommendations may still receive a satisfactory assessment. It is sensible to keep the recommendations on the property maintenance plan, especially if other work is due. A landlord may choose to improve the installation, but should not be told that every C3 item must legally be fixed merely to change the report’s outcome.

FI: the important change introduced in 2026

The meaning and effect of FI have changed in a way that older website guides and quotation templates may not yet reflect. Under the previous model EICR, an FI observation was described as “further investigation required without delay” and could result in an unsatisfactory report. The IET BS 7671:2018+A4:2026 model EICR form instead describes FI as “further investigation is advised” and places it with C3 in the advisory section. According to the IET’s 2026 Wiring Matters article on further investigation, FI alone does not make the overall assessment unsatisfactory.

This does not mean FI is an empty note. It means the inspector has identified a possible issue that cannot be properly characterised without further information, within the inspection’s agreed scope and limitations. In a domestic property, inspectors should normally be able to attribute a C1, C2 or C3 code where the evidence supports one. FI is not intended as a routine substitute for doing the inspection or for describing a known defect. Electrical Safety First’s current Best Practice Guide 4 recommends investigating a genuine FI finding as soon as possible so the uncertainty can be resolved.

Always check which edition and report form was used, particularly if somebody describes an earlier EICR as “failed because of FI”. A properly evidenced C1 or C2 still makes the current A4 report unsatisfactory, irrespective of any separate FI recommendation. Equally, a satisfactory overall tick on the current form should never be used to dismiss a clearly identified possible safety issue that still needs professional attention.

What does FI mean for a landlord in England?

There is a second distinction between the current technical report form and landlord duties. The published GOV.UK guidance on electrical safety standards in the private and social rented sectors still describes FI as further investigation required without delay and tells landlords to ensure necessary investigative work is completed. Its wording has not been fully aligned with the 2026 model form’s new advisory classification. For an occupied rented home, the prudent approach is to obtain the inspector’s written explanation, arrange the recommended investigation promptly and record its outcome, rather than assuming that a satisfactory overall assessment automatically closes the matter.

Where a report identifies required remedial or investigative work for a tenancy covered by the English rules, the government guidance refers to completion within 28 days of inspection and testing, or any shorter period specified. A C1 danger needs immediate safety action regardless of an administrative deadline. Whether a particular A4 FI observation engages a statutory deadline can depend on the report wording and applicable obligations, so landlords and agents should seek a clear written position from the qualified inspector rather than relying on an old template or a generic internet answer.

The separate guide What Happens After an Unsatisfactory EICR covers the practical sequence of arranging work, dealing with dates, obtaining completion evidence and giving documents to the relevant people. The descriptions above help you identify which finding the electrician is referring to before you discuss that process.

How to read the observations section without guessing

Begin with the report date and the edition of BS 7671 identified on the form, then read the summary assessment and the schedule of observations together. One letter on its own is not enough. A useful observation should describe the defect, its location or circuit, and why the condition warrants that classification. The inspection’s extent and limitations matter too; inaccessible areas and agreed restrictions tell you what the report could and could not establish.

For example, “socket dangerous” offers little help in understanding the risk or scoping remedial work. A clearer observation identifies the affected outlet and describes what was found, such as accessible live parts or an absent protective earth. Photographs and relevant test references can help, but a photograph alone cannot establish whether every part of a circuit is safe. Ask the inspecting electrician to explain uncertain wording before obtaining quotations based on assumptions.

Electrical Safety First’s Best Practice Guide 4 explains that the inspector must assign a code based on the actual observation and the installation context. The inspector, not the landlord or a salesperson, is responsible for assigning the code. If a report seems inconsistent, request the technical basis for the classification; do not change codes merely because one outcome is cheaper.

Why similar-looking faults can receive different codes

The same visible feature can mean different things in different surroundings. An older plastic consumer unit does not automatically warrant replacement, and a missing label is not equivalent to exposed conductors. An absence of RCD protection may be an improvement recommendation in one situation but potentially dangerous in another, depending on factors such as circuit use, earthing and the consequences of a fault. The competent inspector must take those conditions into account rather than relying on age or appearance alone.

This also explains why code examples should be read as guidance, not as fixed rules for every home. Two electricians may reach different conclusions because they were given different access, detected different conditions or carried out different tests. A defensible report should make those differences clear enough to assess. It should not be written to support a particular sales proposal.

Is an EICR a quote for rewiring or a new consumer unit?

No. An EICR is an assessment of condition within its stated limitations. It is not a design for the work, a fault-finding investigation of every hidden circuit or a quotation for new equipment. A C2 on one circuit does not automatically prove that every cable in the building must be replaced. A C3 recommending an improvement does not, by itself, turn a planned upgrade into an urgent repair.

Where an observation needs professional assessment or targeted tests, TRACEFORM’s EICR inspection and testing explains the inspection and reporting service, and its electrical fault finding service deals with electrical faults that need diagnosis. These service pages handle booking and commercial questions; the role of this guide is to help a property owner understand what is written on the report before deciding what to ask for.

Who should act on the codes in a rented property?

A landlord or managing agent should establish who ordered the report, who received the danger notification, which restrictions have been placed on use and who can authorise access. A tenant needs clear instructions about what may not be used, without being asked to open electrical equipment or perform tests. The code helps prioritise a conversation with the electrician; it does not replace that professional assessment or the owner’s legal responsibilities.

For routine inspections and portfolio arrangements, TRACEFORM provides landlord electrical services. If a tenant reports an immediate electrical danger rather than a scheduled inspection finding, the guide Landlord Electrical Emergency Obligations addresses the need to respond to that report promptly. These issues are related, but they are not the same search question as understanding the classification codes on an EICR.