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Optional, often oversoldC3: the EICR code where the money usually gets spent
Your EICR came back with a list of observations and a quote for all of them. Only some of them are required by law. C3 means improvement recommended and it is where most of the money goes. Here is how to read the codes and what to do about each.
What you were told: "Your EICR has failed. Here is the quote to bring it up to standard: £2,400."
What the report says: two C2 observations and eleven C3s. The C2s cost £280 to fix. That part is required. The other £2,120 is for the C3s. They are recommendations and none of them is required by law.
The codes, and what each obliges you to do
Fix it now. The inspector should have made it safe before leaving. Not negotiable.
Fix it urgently. Within 28 days for a rented home in England; without unreasonable delay for commercial premises. Get it priced separately from everything else.
Have it investigated promptly. It may resolve to nothing. It may turn out to be a C2. Since Amendment 4 an FI does not fail the report on its own. The inspector decides whether the report is satisfactory.
Nothing is required by law. The installation differs from the current edition of BS 7671 in this respect but it is not dangerous. Typical C3s include old cable colours and a plastic consumer unit. Missing surge protection is another. So is a lighting circuit with no RCD that never leaves the building.
Your options on every C3
Fix it now. Right where the C3 is in a high use area or causes nuisance tripping. Right where it involves RCD protection on circuits the public uses. Right where your insurer has asked.
Add it to planned works. If an electrician is coming anyway, add the C3s then. You pay for one visit instead of two and the labour and materials are combined.
Leave it and monitor. Legal where money is tight. Note it and check it is still a C3 at the next inspection.
My advice
Do the C3s where you can. A qualified electrician has looked at your installation and is telling you what it needs. That is worth listening to.
If the quote feels high or the list feels long, get a second opinion. Ask the free Compliance Buyer assistant at the top of this page. Or ask another NICEIC commercial electrician to look at the report.
The 2026 amendment
BS 7671 Amendment 4 was published on 15 April 2026. It replaced the previous version on 15 October 2026. It now applies to all new work and every new EICR.
It does not oblige you to upgrade an existing installation. An older installation that does not match the new edition is not necessarily unsafe. A contractor who says your wiring now "fails" because the book changed is describing a C3 at most. Real danger is coded C1 or C2 whatever edition is in force.
What you shouldn’t be sold
- "Failed" when the front page says satisfactory. Read the box, not the letter.
- All C3s quoted as required work. Ask for the C1, C2 and FI work priced on its own. Doing the C3s at the same time often saves money because the labour and materials are combined.
- A consumer unit replacement because of an amendment. A safe installation does not become unsafe when the book changes.
Quick answers
- Do I have to fix C3 items on an EICR?
- Not by law. C3 means part of the installation does not meet the current Wiring Regulations but is not dangerous. Most installations more than a few years old have some. The report is still satisfactory with C3s alone. My advice is to do them where you can, because a qualified electrician has recommended them.
- Which codes make an EICR unsatisfactory?
- C1 (danger present) and C2 (potentially dangerous). Since Amendment 4 an FI (further investigation) no longer fails a report on its own. The inspector decides. An FI can still hide a C1 or C2, so have it looked into promptly.
- Does Amendment 4 mean my wiring has to be upgraded?
- No. BS 7671 Amendment 4 replaced the previous version on 15 October 2026. An older installation that does not match the new edition is not necessarily unsafe or in need of upgrading. Differences from the new edition are usually coded C3.
General information, written for the person paying the bill. Opinion is labelled as opinion. Not legal advice. See our editorial standards.