Every EICR report contains a section called "Observations and Recommendations" where the inspector records any issues found during the inspection. Each observation is assigned a classification code that tells you exactly how dangerous the issue is and how quickly it needs to be fixed. Understanding these codes is critical — they determine whether your installation is legally compliant, whether your insurance remains valid, and whether your tenants are safe.
C1 — Danger Present: Immediate Action Required
A C1 code means danger is present and there is a risk of injury from electric shock or fire. This is the most serious classification. Examples include exposed live conductors, incorrectly wired sockets where the live and earth are swapped, or a metal light fitting that is not properly earthed.
If your EICR contains a C1 observation, the inspector should have taken immediate action at the time of the inspection to make the installation safe (such as isolating the affected circuit). Remedial work must be completed as a matter of urgency — technically, the installation should not remain energised with a C1 fault outstanding.
If your EICR report contains any C1 codes, the overall installation is classified as UNSATISFACTORY. You must not rent the property or allow occupancy until the C1 issue is resolved.
C2 — Potentially Dangerous: Urgent Remedial Action Required
A C2 code means the observed issue is potentially dangerous and urgent remedial action is required. While the danger is not immediate (unlike C1), it poses a significant risk if left unresolved. Examples include the absence of RCD protection where required by current regulations, inadequate earthing, or an outdated fuse board that does not provide sufficient circuit protection.
Under the Electrical Safety Standards Regulations 2020, landlords must complete remedial work for C2 observations within 28 days of the EICR. If the inspector specifies a shorter timeframe, that takes precedence.
C3 — Improvement Recommended
A C3 code means the installation does not meet current standards, but the observed issue is not dangerous. Examples include a lack of supplementary bonding in a bathroom (if the main bonding is adequate), or a consumer unit that is technically safe but does not meet the fire-resistant requirements of BS 7671 Amendment 2.
C3 observations are not legally required to be fixed, and they do not make the installation unsatisfactory. However, addressing C3 issues improves safety, future-proofs your property, and may be required by insurers or mortgage lenders. We always recommend discussing C3 observations with your electrician to understand the cost-benefit of remediation.
FI — Further Investigation Required
An FI code means the inspector has identified something that requires further investigation without delay to determine whether it should be classified as C1 or C2. Examples include a circuit with suspiciously high earth loop impedance readings, or signs of damage to cables that cannot be fully assessed without invasive investigation.
FI codes make the installation unsatisfactory, just like C1 and C2 codes. You must arrange further investigation promptly. In many cases, the electrician who carried out the EICR can conduct the follow-up investigation and, if necessary, complete any remedial work.
What Makes an Installation "Satisfactory"?
An electrical installation is only classified as SATISFACTORY if the EICR contains no C1, C2, or FI observations. C3 observations alone do not make the installation unsatisfactory. If your report is unsatisfactory, you must complete remedial work and obtain a new satisfactory certificate before the property can be legally let or occupied.
