What do EICR codes C1, C2, C3 and FI mean?

Each code tells you how serious an observation is and how quickly it needs attention. The electrician records them in the condition report against the circuit or part of the installation where they were found.

C1: danger present, risk of injury. Something is wrong now that could hurt someone. It needs immediate action, and a competent electrician will often make it safe on the spot or advise you to isolate the circuit until it is fixed.

C2: potentially dangerous. It may not be causing harm today, but it could become dangerous if another fault occurs or the installation is used in a certain way. It needs urgent remedial work, so do not leave it for later.

C3: improvement recommended. The installation is not dangerous, but it falls short of current best practice. It is advice rather than a fault, and you can decide when or whether to act.

FI: further investigation required. The electrician could not fully assess something during the inspection and testing, and there is a possibility it is dangerous. It needs looking into without delay.

An EICR comes back as unsatisfactory if it contains any C1, C2 or FI code. One of those is enough, however good the rest of the installation looks. A report with only C3 observations, or no observations at all, can still be recorded as satisfactory.

This matters because the overall outcome is often what gets asked for. Letting agents, mortgage lenders, solicitors and landlords usually want to see a satisfactory electrical installation condition report, not a list of codes. If yours is unsatisfactory, the usual route is to complete the remedial work and have the issues checked and recorded, so the position is clear in writing.

Rules for rented homes and other property types can change, so check GOV.UK for the current position on what landlords must do with a report and how soon.

Every installation is different, so these are general illustrations, not a list of what your report will say.

A C1 might be exposed live conductors that anyone could touch, or a damaged accessory with signs of burning. These are situations where someone could be hurt straight away.

A C2 might be missing or inadequate earthing or bonding, a circuit with a high resistance reading that could stop a protective device operating quickly enough, a cracked or unsuitable consumer unit enclosure, or sockets that could be used outdoors without suitable additional protection. Nothing may have gone wrong yet, but the safety margin has gone.

A C3 might be an older installation that works safely but lacks features now regarded as good practice, or labelling and records that could be clearer. It is worth reading, but it is not an emergency.

An FI often arises when something cannot be traced or tested during the visit, for example a circuit whose route is unclear, or a reading that looks odd and needs more testing to explain.

FI is the code people misunderstand most. It does not say something is definitely wrong. It says the electrician could not prove that part of the installation is safe, and that it has to be checked properly.

The investigation might involve tracing circuits, opening up accessories, or carrying out extra testing. Once the cause is found, the observation is usually recoded or resolved. It might turn out to be harmless, or it might become a C1 or C2 that then needs fixing. Until then, the report stays unsatisfactory, because the safety of that part is unconfirmed.

If you see FI on your report, ask the electrician what could not be assessed and why. Access is a common reason: locked rooms, items blocking the consumer unit, or areas that were not available on the day. Making sure everything can be reached before an inspection can reduce the chance of an FI.

Start with the most serious codes. C1 items come first, then C2 and FI. Ask the electrician to explain each one in plain words and to point out where in the property it is.

Next, get the remedial work priced in writing. Cost depends on the type of work. A single accessory is quite different from rewiring a circuit or replacing a consumer unit. Other factors include the materials needed, how easy it is to reach the cabling, how long the job takes, whether it can be done in one visit, and whether a callout fee, hourly rate or fixed price applies. A written quote that lists each coded item lets you compare like with like.

If you are a landlord, tell your tenants and your letting agent what the report found and what is being done. If you are a homeowner, keep the report with your property papers, because a future buyer may ask for it. Consider whether to deal with the C3 items at the same time as the urgent work, especially if the consumer unit or circuits will already be opened up.

Benfleet Electrical Services provides EICRs and covers Benfleet and the surrounding parts of Essex. Whoever you use, check that they explain their codes clearly and give you a written report you can understand.