Classification codes

C1 and C2 make a report unsatisfactory

Four codes can appear against an observation on your report. Only two of them affect the outcome, and which two changed in 2026, so a good deal of the guidance you will find online is describing the previous position.

England. Codes come from BS 7671, currently at the 2018 edition as amended by A4:2026.

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The four codes

Classification codes

C1 and C2 make a report unsatisfactory

Only C1 and C2 make a report unsatisfactory. C3 and FI were decoupled from that outcome in 2026, so much of the published guidance still describes the old position.

C1Danger present

Risk of injury. Immediate remedial action required. The inspector should make it safe before leaving, or tell you plainly that it is not.

Makes the report unsatisfactory.

C2Potentially dangerous

Urgent remedial action required. Nothing is dangerous right now, but something has to fail for it to become so, and that failure is foreseeable.

Makes the report unsatisfactory.

C3Improvement recommended

Not a fault. Usually something installed to an older standard that was correct at the time. Worth doing, not required, and it does not make the report unsatisfactory.

Does not make the report unsatisfactory.

FIFurther investigation advised

Something was found that could not be fully identified within the extent of the inspection, and it may turn out to be a C1 or a C2. It does not make the report unsatisfactory, but it does mean a question is still open.

Does not make the report unsatisfactory.

An FI not making a report unsatisfactory is not the same as an FI being safe to ignore. Where a report says further investigative work is necessary, the landlord’s 28-day duty is engaged. How that sits with the 2026 change is unsettled. Ask the electrician who signed your report what they meant by it.

This describes the law in England. The Welsh and Scottish positions differ, Scotland's repairing standard also covers portable appliances, which the England duty on private landlords does not. It is general information, not legal advice. Last checked against the primary sources on 27 August 2026.

What changed in 2026

BS 7671:2018+A4:2026 decoupled C3 and FI from the unsatisfactory outcome. Before that amendment, an FI could carry a report to unsatisfactory on its own. It no longer does.

FI was also softened in wording, from further investigation required without delay to further investigation advised.

The practical effect is that two reports listing identical findings can reach different overall verdicts depending on which edition the inspector was working to. If you are comparing an old report with a new one, check the amendment on the front of each.

An FI is not a clean bill of health

It means something was found that could not be fully identified within the extent of the inspection, and it may turn out to be a C1 or a C2 once someone looks properly.

There is an open question here that we are not going to paper over. The landlord regulations impose a 28-day duty wherever a report indicates further investigative or remedial work is necessary. The IET article that introduced the 2026 change does not mention the regulations, landlord duties or that deadline at all, so how the two fit together is genuinely unsettled rather than merely unclear.

Until that is resolved somewhere authoritative, treat an FI as a live question and ask the electrician who signed the report what they meant by it.

Codes are not the whole report

The codes tell you what was found. The schedule of test results tells you what was measured, and the limitations tell you what could not be reached. A report with codes and no schedule is a verdict with no working shown.

What you get

A report records circuits, codes and limitations

The verdict is the least useful part. What matters is the schedule of test results behind it, the coded observations, and an honest record of anything the inspection could not reach.

A ticked box and nothing else is a verdict with no working shown. Worth knowing before you accept one, whoever arranged it.

Electrical Installation Condition ReportBS 7671

Schedule of circuit details

1Lighting, ground floor6A Type B
2Lighting, first floor6A Type B
3Sockets, ring final32A Type B
4Cooker32A Type B
5Immersion heater16A Type B
6Outbuilding supply20A Type B

Observations and classification codes

  • C2No RCD protection to the outbuilding supply.
  • C3Consumer unit is not of a non-combustible construction.

One C2 present, so this report reads unsatisfactory. The C3 alone would not have made it so.

An illustration, not a real report. No address, reference or signature: those belong to a real inspection.

Who does the work

Every electrician clears six checks

We do not carry out the inspection. We put you in touch with an electrician who does. An EICR is worth what the person signing it is worth, so these checks are the product. Each is verified against the issuing body's own register, not taken from a logo.

Competent to inspect and test

Inspection and testing carries its own qualification. A good installer is not automatically the right person to sign a report.

Registered with a competent person scheme

Checked on the scheme's own public register, not a badge on a website.

Public liability insurance, in date

We check the certificate and the expiry date, not just that one exists. A lapsed policy is the most common reason to turn someone away.

Reports that carry their schedule

We look at an electrician's reports before sending them a job. The schedule of results is the part worth checking.

Working to the current standard

BS 7671 as currently amended. The 2026 amendment changed what makes a report unsatisfactory, and not everyone has caught up.

A public record worth reading

We read what previous customers wrote instead of counting stars. We publish no figure of our own, because we have none.

Scheme registration and insurance details come with your quote, so you can check them against the public register yourself. How we choose electricians sets out every check, including what gets someone turned away.

Next step

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If your current report has months left, that is what you will be told.

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Questions

Codes explained questions

Does one C3 mean I have to do work?

No. A C3 is an improvement recommended, usually something installed to an older standard that was correct at the time. It is worth considering and it is not a requirement.

Can I ignore an FI?

No. It does not make the report unsatisfactory, which is a different thing from being safe to ignore: it means a question is still open. Ask the electrician who signed the report what they intended by it.

My old report failed on an FI. Would it pass now?

Possibly, on the overall verdict alone, because FI no longer produces an unsatisfactory outcome. Nothing about the installation has changed, though, and the finding that prompted the code is still there.

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Summary of the condition of the installation
Extent of the installation coveredWhole installation, all circuits
Agreed limitationsConcealed cable, floors not lifted
Overall assessmentUnsatisfactory
Recommended next inspectionWithin 5 years

An unsatisfactory result starts a 28 day clock on a rented property. The report says what was found, so you can get it priced.

Example only. A real summary carries the property, the date and the signature.
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