EICR Codes Explained — C1, C2, C3 and FI for London Landlords

C1 — danger present, risk of injury, immediate action required. C2 — potentially dangerous, urgent remedial within 28 days. C3 — improvement recommended, best-practice upgrade, not a fail. FI — further investigation required, the inspector could not conclude without intrusive work or a return visit. Only C1, C2 and FI make an EICR unsatisfactory.

The attending inspector, signing the report under their personal NICEIC, NAPIT, ELECSA or STROMA registration. The certification body audits the contractor annually; the inspector carries personal accountability for every code applied. There is no algorithm — coding is a judgement informed by BS 7671 and Best Practice Guide 4 from Electrical Safety First.

Not formally — there is no appeal court for EICRs. In practice you commission an independent second-opinion review from a different NICEIC contractor. If the second opinion reaches a different conclusion you can challenge the first inspector through their certification body (NICEIC complaints process) and use the second EICR as your certificate of record.

An EICR is marked unsatisfactory the moment a single C1, C2 or FI is recorded on the schedule of inspections. Multiple C3 codes alone never produce an unsatisfactory result — C3 is an improvement recommendation, not a defect. The cover page of the certificate carries the binary 'Satisfactory / Unsatisfactory' result.

It means the inspector found a condition they could not fully assess in the time and access available — typically a buried cable route, an inaccessible junction box, or an undocumented historical alteration. FI is treated as a fail until resolved. The investigation is usually a 1–2 hour return visit, often involving lifting floorboards or removing a section of plasterboard.

The day after the inspection date printed on the EICR. The Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020 require the landlord to (1) supply the EICR to existing tenants within 28 days, (2) complete remedial work within 28 days or the period specified on the report (whichever is shorter), and (3) supply written confirmation of the remedial work to the tenant and, on request, the local housing authority.

BS 7671 allows multiple observations against a single circuit, each with its own code. We list them separately on the schedule so you can see exactly what's been found and what's been remedied. The highest-severity code drives the overall result — one C2 on a circuit with three C3s still produces an unsatisfactory EICR.

Not always. For minor remedials touching one or two circuits, we issue a Minor Electrical Installation Works certificate that supersedes the codes on those circuits — your existing EICR stands. For consumer-unit-level work or remedials touching more than three circuits, a full re-inspection and a fresh EICR is the cleaner audit trail.

The codes themselves are identical — BS 7671 applies to every installation. What differs is the inspection methodology (HMOs and commercial sites are typically 100% tested rather than sampled), the inspection interval (HMOs every 5 years, higher-risk commercial every 3 years) and the regulatory framework (PRS Regs 2020 for rented homes, Electricity at Work Regs 1989 for workplaces, HMO licensing conditions on top).

The grey area is where a defect is potentially dangerous in normal use but not actively presenting danger at the moment of inspection. A burnt accessory with no exposed conductor sits on the C1/C2 boundary; a missing supplementary bond in a bathroom sits on the C2/C3 boundary. We refer to Best Practice Guide 4 from Electrical Safety First — the industry-standard tie-breaker for exactly these cases.