EICR C1, C2, C3 and FI Codes Explained

Use the labelled summary below as a quick orientation. Colour accents are not the only cue — each code name is written in text. Full explanations follow in the sections after this summary.

An EICR lists observations. Where an observation needs a severity signal, the inspector assigns a classification code: C1, C2, C3 or FI. The code is not a DIY repair instruction and it is not a substitute for reading the observation text.

Broadly: C1 signals danger present; C2 signals a potentially dangerous condition; C3 recommends improvement; Under the A4:2026 report format, FI means further investigation is advised. Overall satisfactory or unsatisfactory outcomes are decided from the report as a whole — not from guessing a single code in isolation.

Codes sit beside numbered observations in the schedule of inspections and testing. The observation describes what was found; the code communicates urgency to people who are not electricians.

Assignment depends on the installation, how it is used, what could be inspected safely on the day, and competent comparison against applicable requirements associated with BS 7671. Two properties can share a similar-sounding defect and still receive different codes if the risk context differs.

This hub explains the code system. Separate pages cover unsatisfactory outcomes for landlords, remedial work after a failed report, and detailed topics such as C2 meaning, RCD absence, SPD, AFDD, bonding and specific bathroom scenarios.

C1 means the inspector recorded a condition that presents danger. Immediate action is typically required — often including making the installation safe before other work continues.

C1 observations contribute to an unsatisfactory outcome. They are not “cosmetic notes”. Treat the observation text and any isolation advice on the report as authoritative for that property.

Do not attempt electrical DIY based on a blog summary. Arrange competent attention using the observation numbers on your report.

C2 means a condition is potentially dangerous. Remedial work or further controlled action is typically needed before the installation can be considered satisfactory.

One or more C2 observations usually drives an unsatisfactory overall result. Urgency can still vary by location and use of the circuit — prioritisation should follow the report and competent advice, not a generic ranking invented online.

For a deeper supporting article on C2 wording and landlord follow-up, see the dedicated C2 guide. That article does not replace this hub’s overview role, and this hub does not retarget the C2 article’s primary keyword.

C3 recommends improvement. It signals that something could be enhanced for safety or alignment with current practice, without the same urgency signal as C1 or C2.

A C3 observation alone does not make a report unsatisfactory. You may still choose to schedule improvement work for risk reduction, future-proofing or insurer or managing-agent expectations — those are separate decisions from the code itself.

FI concerns an apparent deficiency or unresolved potential safety issue that could not be fully determined within the inspection. It should not be used merely because a circuit is unidentified or access is limited. Read the observation and report format.

Under BS 7671:2018+A4:2026, an FI observation means further investigation is advised. It does not itself make the EICR unsatisfactory. C1 or C2 does. C3 is an improvement recommendation and does not itself make the assessment unsatisfactory.

Check the edition used for your report. Earlier report formats may treat FI differently. For rented property in England, any requirement for further investigative work must also be considered under the applicable legal duties; the overall report outcome does not replace that duty.

A satisfactory outcome means the installation was assessed as satisfactory for continued use within the recommendation period stated on that report — subject to any limitations recorded.

An unsatisfactory outcome means observations prevent a satisfactory result. C1 and C2 findings typically contribute to that result. FI items may also prevent a satisfactory conclusion until investigation is complete, depending on the report. C3 alone does not create an unsatisfactory outcome.

Landlord-specific process guidance — including practical next steps after an unsatisfactory report — lives on the unsatisfactory EICR page. This hub does not replace that owner.

A code does not name the exact remedial method, the materials list, or a fixed legal deadline that applies to every property type. It does not price the repair. It does not guarantee that every named defect always receives the same code.

Observation text, limitations, circuit identification and the inspecting electrician’s notes remain essential. If a managing agent, insurer or lender asks for evidence, they usually need the report itself — not a paraphrase from a guidance page.

Examples help people recognise patterns; they do not invent universal code shortcuts. The same named defect can be coded differently where risk, location, protective measures or access differ.

An exposed live conductor that presents immediate danger is typically associated with C1 thinking — but the report wording and any isolation action at the property govern what you must do next, not a blog example.

Missing or inadequate RCD protection on a socket circuit may appear as a C2 or another classification depending on the circuit use, environment and the inspector’s assessment under the applicable requirements. Dedicated articles cover RCD, SPD, AFDD and bonding questions in more depth without replacing this hub.

A recommendation to improve labelling, arrange cables or update documentation can appear as C3. That does not, by itself, create an unsatisfactory overall result.

An inaccessible board or a circuit that cannot be isolated may need a recorded limitation. It is not automatically FI. Where an observation identifies an unresolved potential safety issue, follow the inspector’s explanation and the applicable report format rather than guessing a repair from the code letter.

“C3 means the property failed.” It does not. C3 alone does not make a report unsatisfactory.

“FI always makes an EICR unsatisfactory.” Not under the A4:2026 format. Investigation is advised, and any applicable landlord obligation must be considered separately. Check the report edition and observation.

“The code is the repair method.” Codes communicate urgency. Observation text and competent quotation define the work.

“Every London flat gets the same codes for the same defects.” Classification depends on context and professional judgement. Two similar-sounding issues can be coded differently for good technical reasons.

You receive a written EICR with outcomes and coded observations where applicable. Read each observation. Prioritise danger and potentially dangerous items. Arrange further investigation where FI appears. Plan improvement work for C3 items if you choose to.

Customers should treat the issued report as the property-specific authoritative record. Guidance pages explain patterns; they do not override the document you were given.

Remedial work is a separate scope from the inspection. Quotes should reference observation numbers so contractors address the same findings. Verification after remedial work depends on what was corrected — it is not automatic and is not included in the original inspection fee unless agreed separately.

Use the remedial-work page for process ownership. Use this hub to understand why codes appear and how they relate to outcomes.

Issue-specific articles remain the owners of their narrow topics. Use them after you understand the code system:

• C2 meaning — detailed supporting article
• RCD, SPD and AFDD — device-specific assessment guidance
• Missing bonding and shaver-socket scenarios — context-specific issues
• Report example — how sections are organised (illustrative, not a client certificate)
• Unsatisfactory outcome process — landlord-focused next steps
• Remedial work — inspection versus repair separation

If you need a London EICR, check residential pricing or book an appointment. If you already hold an unsatisfactory report, start with the unsatisfactory and remedial guidance, then contact the team with observation numbers ready.

Inspections are carried out by qualified electrical contractors. Contractor details can be confirmed when your appointment is arranged.

This page was editorially reviewed on 2026-08-01. It provides general operational guidance for London property decision-makers and is not personalised legal advice.

Always read your own report and seek competent advice for your property. Classification and renewal decisions depend on installation condition, use, applicable rules and professional judgement.