What is a C2 code on an EICR?

C2 is the code that turns most reports unsatisfactory, so it is worth understanding precisely. The sections below explain what "potentially dangerous" means and how it sits between C1 and C3.

What 'potentially dangerous' means

A C2 identifies a fault that is not dangerous right now but could become so. The model report wording is "Potentially dangerous — urgent remedial action required." The risk is conditional: the installation is generally usable, but if a further fault developed, or if particular circumstances arose, the C2 condition could lead to a shock or fire.

A useful way to think about it is fault tolerance. A C1 is dangerous as it stands. A C2 typically means a protective measure is missing or compromised, so the installation is relying on everything else staying perfect — and if it does not, harm could follow. That is enough to require urgent correction, even though nothing is live and exposed today.

The conditional nature of the risk is what people most often misread. Because a C2 installation can be used day to day without anything obviously wrong, it is tempting to treat it as less pressing than it is. But the code is not about how the installation behaves on a normal day — it is about what happens when something else fails. A missing earth connection, for instance, causes no trouble at all until a fault makes a metal casing live; at that moment the absent protection is the difference between a tripped circuit and a serious shock. A C2 is the inspector saying that the installation is being kept safe by luck or by an intact second layer that should not be relied upon. That is precisely why "urgent" appears in the wording even though the hazard is not yet present: the point of fixing a C2 is to restore the protection before the day it is needed, not after.

Examples of C2 faults

C2 codes usually relate to missing or inadequate protection rather than openly exposed live parts. Typical examples include:

• No earthing or main/supplementary bonding where it is required, so metalwork could become live under fault conditions.
• No RCD protection on circuits that should have it — for example socket circuits that could supply equipment used outdoors.
• Damaged cable where the insulation is compromised but live conductors are not yet exposed.
• Inadequate connections or accessories that are deteriorating.
• An accessory or enclosure that no longer provides proper protection against contact.

Because these involve compromised safety measures, they are treated as urgent — the installation should not be left relying on a missing layer of protection.

How C2 affects the result and what to do

Any C2 code makes the overall EICR result unsatisfactory, alongside C1 and FI. In practice C2 is the most common reason a report fails, particularly in older homes that predate current RCD and bonding requirements.

The required response is urgent remedial work: have a qualified electrician correct each C2 item and confirm in writing that it has been resolved. Once the C2 (and any C1 or FI) issues are fixed, the installation can be considered satisfactory, often evidenced by a remedial confirmation or a fresh certificate.

Because a C2 rarely sits in isolation, it is worth reading the report as a whole before instructing work. Several C2 items in an older home frequently share a single root cause — most often a consumer unit that lacks modern protection — so addressing that one element can clear a cluster of codes at once. Tackling each observation as a separate job, by contrast, can cost more and still leave the underlying shortfall in place. A short conversation with the electrician about which C2 items stem from the same source is usually the quickest way to see whether a single piece of work would resolve several at once, and it often makes the remedial route both cheaper and simpler than the list of codes first suggests.

For privately rented homes in England, the Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020 require the landlord to complete remedial work within 28 days of the report, or sooner if the report specifies, and to provide written confirmation to the tenant and local authority. For owner-occupiers there is no statutory deadline, but because a C2 represents a genuine safety shortfall it should not be left indefinitely.

Why so many older homes pick up C2 codes

If your report came back unsatisfactory with one or more C2 codes, it is worth understanding why this is so common rather than treating it as a sign the property was badly built. An EICR judges the installation against the current edition of BS 7671, and the most significant changes over the years have been around protection against electric shock — exactly the area C2 codes tend to flag.

The recurring causes of C2 codes in older properties are:

• Missing RCD protection: for years, socket circuits and circuits serving outdoor equipment did not require an RCD. Today their absence is generally a C2, because the protective layer that would limit a shock is simply not there.
• Inadequate bonding: main protective bonding to gas and water services, and supplementary bonding in bathrooms, was historically applied less consistently. Where it is missing or undersized, metalwork could become live under fault conditions.
• Ageing consumer units: older boards may lack the protective devices now expected, and their condition can attract a C2.
• Deteriorating cable and connections: insulation that has begun to break down, or connections that are loosening, compromise safety without yet being openly dangerous.

The practical takeaway is that a C2-driven unsatisfactory result usually reflects an installation that has fallen behind current standards rather than one that is actively failing. Addressing the C2 items — often by adding RCD protection, upgrading the consumer unit, or improving bonding — brings the installation back up to standard and turns the result satisfactory.

Frequently asked questions

Sources & further reading

• Electrical Safety First — EICR codes and what they mean
• NAPIT — EICR classification codes guidance

Figures on this page are typical UK ranges drawn from published sources and depend on your specific property. They are guidance, not a quotation. Legal duties are summarised for guidance — confirm the current position on GOV.UK.