What Is an EICR? C1, C2 and C3 Codes

An EICR is a safety inspection of your wiring. Here is what the C1, C2, C3 and FI codes mean, which ones fail the report, and what you must fix.

Written by Jack Snelling, qualified electrician Plain English, no jargon Updated June 2026

An EICR (Electrical Installation Condition Report) is a thorough inspection and test of the fixed wiring in a property, the cables, sockets, switches, fuse board and circuits. The electrician records the condition of each part and gives the whole installation an overall “satisfactory” or “unsatisfactory” result. Any faults are graded with a code: C1, C2, C3 or FI. C1 and C2 are the serious ones that cause a fail.

What does an EICR actually check?

It is not a quick look round with a screwdriver. A proper EICR involves both a visual inspection and live electrical testing. The electrician checks things like:

  • The fuse board (consumer unit) and whether it provides modern protection such as RCDs or RCBOs.
  • The condition and type of cabling, including old rubber or fabric-insulated wiring that should have been replaced decades ago.
  • Earthing and bonding, which keep you safe if a fault develops, including bonding to gas and water.
  • Every circuit, tested for things like insulation resistance and loop impedance, to confirm it will disconnect safely under fault.
  • Sockets, switches and accessories for damage, signs of overheating or unsafe DIY work.

At the end you get a written report listing what was found and an overall verdict.

What do the EICR codes mean?

There are four codes, and understanding them is the key to reading your report sensibly rather than panicking.

  • C1 — Danger present. There is a risk of injury right now. This is the most serious code. Exposed live parts or a similar immediate hazard would be a C1, and a good electrician will make it safe on the spot where possible.
  • C2 — Potentially dangerous. Not an immediate danger, but it could become dangerous, for example no earth on a circuit, or no RCD protection where one is now required. C2 is the most common reason a report comes back unsatisfactory.
  • C3 — Improvement recommended. Not dangerous and does not fail the report. It flags something that does not meet the current standard but is safe, for example an older but functional arrangement. You do not have to act on a C3, though it is often sensible.
  • FI — Further investigation required. Something needs a closer look before it can be coded properly, and it affects the safety of the installation. An FI also makes a report unsatisfactory until resolved.

So a report passes (is “satisfactory”) only if it has no C1, no C2 and no FI. C3s alone do not fail it.

My report came back unsatisfactory — what now?

It means at least one C1, C2 or FI was found and remedial work is needed. For landlords in Scotland, the remedial work flagged must be put right so the installation meets the Repairing Standard, and where that work replaces the consumer unit or a circuit you are given an Electrical Installation Certificate (EIC) for it. The certificate then needs to reflect a satisfactory result before you are compliant.

This is where dealing with one honest electrician end to end pays off. If Jack finds a fault on your inspection, you get a clear explanation of what it is, why it is coded the way it is, and a straight quote to fix it, with no scare tactics and no inventing problems that are not there. Several of the codes people worry about, like a missing RCD, are resolved simply by upgrading the fuse board.

Is a C2 always expensive to fix?

Not necessarily. Some C2 items are a quick remedial, like adding bonding or replacing a damaged accessory. Others, like a board with no RCD protection across a property that has had bits added over the years, point to a fuse board upgrade or partial rewire. The honest answer is that it depends entirely on what was found, which is exactly why the report itemises each issue rather than giving you one vague verdict. You will always get a written quote so you can decide.

How long does an EICR take and how soon is the report back?

A typical domestic EICR takes a few hours depending on the size of the property and the number of circuits. With Snelling Electrical the report is returned quickly, photographed and itemised, so landlords have it in good time to stay compliant with the Repairing Standard. You can see pricing and book on the landlord EICR page.

Want it looked at properly?

Jack quotes it, Jack does it, Jack signs it off. Written quote within 24 hours, no obligation.

Quick answers

Frequently asked

Does a C3 mean my property fails the EICR?

No. C3 is "improvement recommended" and does not cause a fail. Only C1, C2 and FI codes make a report unsatisfactory.

What is the difference between a C1 and a C2?

A C1 is an immediate danger present right now. A C2 is potentially dangerous, meaning it could become a hazard but is not live and dangerous at this moment. Both must be remedied.

How long is an EICR valid for?

For private rentals in Scotland, at least five years, or sooner if the report recommends an earlier re-inspection. Owner-occupiers are advised to test every ten years.

Can you fix the faults you find on the same visit?

Minor remedials can sometimes be done there and then. Larger work, like a fuse board upgrade or a partial rewire, is quoted in writing so you can decide before any work goes ahead.

Still not sure? Just ask Jack.

Send him the question on WhatsApp and you'll get a straight, plain-English answer, usually the same day. No call centre, no pressure.

qualified electrician · 24 hours, 7 days a week · Based in Dalgety Bay, Fife