An EICR code is not an opinion. C1, C2, C3 and FI are fixed definitions from BS 7671, and the one an electrician writes down decides whether an installation is safe or unsafe in law. Get the code wrong and a dangerous circuit stays live, or a landlord misses a 28-day deadline. Here is exactly what each one means and what you must do the moment you find it.
Guide · Electrical
EICR codes explained.
C1, C2, C3 and FI decide whether an installation is safe. This guide explains what each code means, what you must do when you find one, and what the law requires of landlords after an Unsatisfactory report.
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The four codes
What each condition code means
C1
Danger present
Risk of injury right now. Advise the client in writing not to use the affected installation. Makes the EICR Unsatisfactory.
C2 / FIAction required
C2 is potentially dangerous; FI needs further investigation. Both make the EICR Unsatisfactory until resolved.
C3Improvement recommended
Not dangerous and does not make the report Unsatisfactory. The client decides whether to act on it.
The law
Remedial timescales
Under the Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020, landlords must complete remedial work within 28 days of receiving an Unsatisfactory EICR, or sooner if the report says so, then provide written confirmation to the tenant. Every C1 and C2 is a legally unresolved obligation until done and confirmed.
In the field
Flag C1 and C2 live
Electricians record observations through a WhatsApp conversation: no app, no login. The moment a C1 or C2 is entered it is flagged live on the dashboard, so the office can contact a landlord immediately rather than waiting hours for the PDF. Red, amber and green status make severity visible across every live job.
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The short version
- C1 means danger is present. Advise the client in writing not to use the affected installation.
- C2 means potentially dangerous. The EICR is Unsatisfactory, though immediate shutdown is not always required.
- C3 means improvement recommended. It does not make the EICR Unsatisfactory.
- FI means further investigation is needed. The EICR is Unsatisfactory until the investigation is complete.
- Landlords have 28 days to fix an Unsatisfactory EICR, or sooner if the report says so.
- The codes come from BS 7671, the IET Wiring Regulations. They are definitions, not judgement calls.
The framework
Four codes, one outcome
An Electrical Installation Condition Report uses a small set of standardised codes to describe each observation. These codes come from BS 7671, the IET Wiring Regulations, and their meanings are not matters of opinion. An electrician cannot upgrade a C2 to a C3 because the client seems unbothered. The code describes the condition of the installation, not the client's tolerance for risk.
Codes are assigned at the observation level. The overall EICR outcome, Satisfactory or Unsatisfactory, is then decided by which codes appear on it.
- C1 - Danger present, risk of injury. Makes EICR Unsatisfactory: Yes.
- C2 - Potentially dangerous. Makes EICR Unsatisfactory: Yes.
- C3 - Improvement recommended. Makes EICR Unsatisfactory: No.
- FI - Further investigation required. Makes EICR Unsatisfactory: Yes.
C1
Danger present
A C1 means danger is present and there is a risk of injury. It is the most serious code an electrician can assign. This is not a warning about what might happen one day. It describes a real risk right now.
Common C1 findings: exposed live conductors, missing protective devices, damaged wiring with exposed cores, or a complete absence of earthing where earthing is required.
Find a C1 and you must advise the client in writing not to use the affected part of the installation until remedial work is done and the installation re-inspected. That is a professional obligation, not a courtesy. If you can make it safe on the spot, by isolating the dangerous circuit for example, do so. If you cannot, make the danger clear before you leave. Any electrician who finds a C1 and says nothing has failed in their duty of care.
C2
Potentially dangerous
A C2 means the observation is potentially dangerous. The risk is not immediate the way a C1 is, but the defect could turn dangerous through deterioration, a developing fault, or interference by an untrained person.
Common C2 findings: inadequate protection against mechanical damage, absence of RCD protection where it is now required, incorrect cable sizes, and wiring methods that no longer meet current standards.
A C2 makes the EICR Unsatisfactory. The installation does not always need shutting down on the spot, but remedial work is required. In a rental property, the landlord must complete that work within 28 days, or sooner if the EICR specifies a shorter period.
The line between C1 and C2 matters in practice. C1 means tell the client to stop using the affected circuit. C2 means tell the client work is needed. Both make the report Unsatisfactory. Neither lets anyone do nothing.
C3 and FI
Recommended, and not yet known
A C3 means an improvement is recommended. The installation is not dangerous. It falls short of current standards in some respect, but it was installed under older regulations and is not creating a hazard as it stands. C3 confuses clients most: they assume something must be done, but it does not make the EICR Unsatisfactory. A report with only C3 observations comes back Satisfactory. The recommendation is genuine, but it is not a requirement. Upgrading is often simple: adding RCD protection to an older installation, or swapping a socket outlet near a sink for an RCD-protected one. The client's call.
FI stands for Further Investigation. You use it when you cannot determine the condition of part of the installation during inspection and testing: concealed wiring, an inaccessible enclosure, an anomalous test result. FI makes the EICR Unsatisfactory until the investigation is complete and the FI resolves into a condition code, whether C1, C2, C3, or satisfactory. Never misuse FI to dodge a difficult call. When you raise one, make the scope clear: what must be inspected, what access is needed, and the consequence of not investigating.
The law
Timescales and what the report must say
The EICR does not just record condition codes. It must state the recommended period for the next inspection and testing. With no defects, that is typically 10 years for domestic and 5 years for commercial. Where C1 or C2 observations appear, the report should specify the period within which remedial work must be done.
Under the Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020, landlords must complete remedial work within 28 days of receiving an Unsatisfactory EICR, or within any shorter period stated in the report. They must then obtain written confirmation from the electrician that the work is done and the installation is now satisfactory, and pass that confirmation to the tenant.
An EICR is not a document you file and forget. Every C1 and C2 on it is a legally unresolved obligation until the work is done and confirmed.
In the field
How Quickler flags C1 and C2 live
Electricians using Quickler for EICR work record observations through a WhatsApp conversation: no app to install, no login to remember. The moment a C1 or C2 code is entered, it is flagged live on the dashboard. The office sees it in real time, not when the engineer gets back at the end of the day.
That matters most on C1 findings. Raise a C1 at a rental property and the office can call the landlord straight away, rather than waiting for the PDF to land in an inbox hours later. The dashboard uses red, amber and green status to make severity visible at a glance across every live job.
PDF export happens at the end of the workflow. The certificate reaches the client by one-click email straight from the job record. Want the wider picture? See EICR software for electricians, the EICR checklist, and EICR for rental properties.
Questions, answered
What does C1 mean on an EICR?
C1 means danger is present and there is a risk of injury. The electrician must advise the client not to use the affected part of the installation until remedial work is done. A C1 makes the EICR Unsatisfactory and requires immediate action.
What is the difference between C2 and C3?
C2 means potentially dangerous: the defect is not an immediate danger but could become one. C3 means improvement is recommended but the installation is not dangerous. A C2 makes the EICR Unsatisfactory. A C3 on its own does not.
What does FI mean on an EICR?
FI stands for Further Investigation. It is used when the electrician cannot determine the condition of part of the installation without additional testing or access. An FI makes the EICR Unsatisfactory until the investigation is complete and a condition code can be assigned.
How long does a landlord have to fix a C2?
Under the Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020, landlords must complete remedial work within 28 days of receiving the EICR, or sooner if the report specifies a shorter timescale. A C1 typically requires immediate action.
Electrical compliance