EICR codes explained: C1, C2, C3 and FI

An EICR classifies every defect it records with one of four codes. C1 means danger is present and needs dealing with immediately. C2 means the defect is potentially dangerous and needs remedying urgently. C3 means an improvement is recommended but the installation can stay in service. FI means further investigation is required without delay. Any C1, C2 or FI makes the overall report unsatisfactory; a report whose only observations are C3s is still satisfactory.

What does C1 mean? Danger present

A C1 is the one that cannot wait: exposed live parts, a live conductor where fingers can reach it, that order of problem. The inspector should make the immediate danger safe before leaving, or where that is not possible, tell the person responsible for the installation straight away and record having done so. A C1 is not a discussion about budgets; it is the reason the inspection exists.

What does C2 mean? Potentially dangerous

A C2 is a defect that is not dangerous at the moment the inspector looks at it, but plausibly becomes so: a missing earth connection, a damaged accessory that could expose live parts, protective devices that would not do their job under fault conditions. "Urgent remedial action required" is the phrase the trade works to. For a landlord in England, a C2 on a rental property's report starts a legal clock: the remedial work must be done within 28 days, or sooner if the report says so, with written confirmation to the tenant and, if the council asks, to them too.

What does C3 mean? Improvement recommended

A C3 says the installation does not meet the current edition of BS 7671 but is not unsafe as found. Older installations collect C3s naturally, because the regulations move on and installations do not have to be retrofitted to every new edition. No socket outlet RCD protection in an older property is the classic example. A C3 is worth pricing for the client while you are there, but it does not fail the report, and an electrician who codes every departure from the latest edition as a C2 is failing installations that are legally and practically fine.

What does FI mean? Further investigation required

FI is for the things the inspection uncovered but could not resolve within its agreed extent: readings that make no sense until something is dismantled, evidence of a buried problem, circuits that could not be identified. It is not a soft option for "ran out of time": an FI makes the whole report unsatisfactory precisely because an unexplained anomaly might be hiding a real danger. The investigation should follow without delay, and it is chargeable work.

Satisfactory or unsatisfactory: what turns on it

Worst code on the report	Overall assessment
C1, C2 or FI anywhere	Unsatisfactory
C3 only, or no observations	Satisfactory

For rented homes in England, the Electrical Safety Standards in the Private Rented Sector Regulations 2020 require an inspection at least every five years, and an unsatisfactory report obliges the landlord to complete the remedial work within 28 days or the shorter period the report states. Scotland's rules for private tenancies work to the same five-year rhythm. For everyone else, unsatisfactory is not a legal order, but it is a written record, from a competent person, that the installation needs money spending on it, and insurers and buyers read them.

Getting the codes right on the report

Coding is judgement, and two competent inspectors can disagree at the margins, which is why the wording of each observation matters as much as the code. Say what was found, where, and why it earns the classification, with the regulation it offends. A report that reads "various defects (C2)" helps nobody and defends nobody. This is also where good software earns its keep: when the report suggests wording, a code and the regulation reference as you type the defect, and marks the schedule of inspections to match, the observations come out consistent across every report you sign rather than depending on how tired you were that afternoon.