EICR codes explained: C1, C2, C3 and FI — what they actually mean
An Electrical Installation Condition Report (EICR) grades everything the inspector finds using four classification codes. Two of them fail the report, one is only advice, and one means "we don't know yet". Here's what each code means in practice — for electricians writing them and for landlords and homeowners reading them.
The four codes
Observations on an EICR are classified under BS 7671 as follows:
- C1 — Danger present. Risk of injury exists now. The inspector should make it safe immediately or advise immediate action (for example, exposed live parts).
- C2 — Potentially dangerous. Not an immediate danger, but likely to become one; urgent remedial action is required (for example, no earthing to a circuit).
- C3 — Improvement recommended. Not dangerous and not a failure — the installation doesn't meet current standards but is safe to continue using (for example, absence of RCD protection on an older but sound installation).
- FI — Further investigation required without delay. Something was found that could not be fully assessed during the inspection and needs investigating promptly.
Which codes fail an EICR?
A report is Unsatisfactory if it contains any C1, C2 or FI observation. C3 items alone do not fail a report — an EICR full of C3s is still Satisfactory.
This is the single most misunderstood point: C3 is advice, not a defect. Good inspectors use it honestly rather than inflating observations to failures.
How often is an EICR needed?
Private rented homes in England: at least every 5 years (or at change of tenancy if the report recommends it) under the Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020. Landlords must give the report to tenants and, where remedial work is required (C1/C2/FI), complete it within 28 days — or sooner if the report says so — and obtain written confirmation.
Owner-occupied homes: guidance is at least every 10 years, or at change of occupancy. Businesses and other premises have their own recommended intervals.
Writing EICRs without the evening paperwork
For electricians, the report itself is the slow part: the observation schedule, the circuit details and test results, and deriving the outcome. TradeHub OS builds the EICR on site — observations with C1/C2/C3/FI codes, a full circuit schedule (OCPD, cable csa, R1+R2, insulation resistance, Zs, RCD times), the overall outcome derived automatically from your codes, your registration number and drawn signature on the PDF — linked straight to the job, quote and invoice.
This guide is general information for UK trades and landlords, not legal advice. Always refer to the current regulations and official guidance from the HSE, Gas Safe Register or your competent-person scheme.
