EICR codes explained: C1, C2, C3 and FI
Every observation on an Electrical Installation Condition Report gets a code. The codes decide whether the installation is satisfactory — and how urgently the client needs to act.
The four codes
| Code | Meaning | Action |
|---|---|---|
| C1 | Danger present. Risk of injury. | Immediate remedial action. Make it safe before leaving — isolate the circuit and tell the person responsible. |
| C2 | Potentially dangerous. | Urgent remedial action required. |
| C3 | Improvement recommended. | Not dangerous; doesn’t make the report unsatisfactory on its own. |
| FI | Further investigation required without delay. | Something couldn’t be fully assessed during the inspection and needs investigating. |
Satisfactory or unsatisfactory?
If the report has any C1, C2 or FI, the overall condition is unsatisfactory. A report with only C3s (or no observations) can be satisfactory.
Typical examples
| Example | Usual code |
|---|---|
| Exposed live parts that can be touched (e.g. broken accessory) | C1 |
| Incorrect polarity | C1 or C2 depending on the risk |
| No RCD for additional protection on sockets likely to supply outdoor equipment | C2 |
| Absence of main protective bonding to incoming gas or water | C2 |
| Zs exceeds the maximum for the protective device | C2 |
| No RCD protection on cables concealed in walls (installed to an older edition) | C3 (in many cases) |
| Lack of a surge protective device | C3 (in many cases) |
| Circuit that couldn’t be traced or tested | FI |
Coding is a matter of the inspector’s judgement for the specific situation. Industry guidance such as Electrical Safety First’s Best Practice Guide 4 gives detailed examples.
iZapp’s EICR app has observation coding built in, with a regulation library and PDF certificates you can send straight to the client.
Frequently asked questions
Does a C3 fail an EICR?
No. C3 means improvement recommended. On its own it doesn’t make the report unsatisfactory.
What makes an EICR unsatisfactory?
Any C1, C2 or FI observation.
What should I do with a C1?
Make the danger safe immediately — usually by isolating the affected part — and tell the person responsible, ideally in writing with a danger notification.
Last updated 2026-10-14. Training summary of BS 7671 and IET Guidance Note 3 practice, written by NAPIT-registered electricians. Always check the current edition and amendment of BS 7671 and your scheme’s requirements.