EICR Certificate: What Do They Check?

You've booked an EICR, or someone has told you that you need one, and now you're wondering what actually happens when the engineer arrives. It's a fair question. An EICR certificate what do they check covers is more than a quick glance at your fuse box, and knowing what's involved helps you understand the report you get back, and why certain issues get flagged as urgent while others don't.

In short, what does an EICR check comes down to the condition and safety of your fixed wiring, consumer unit, sockets, switches, and earthing arrangements against the current wiring regulations (BS 7671). The engineer inspects for damage, wear, outdated components, overloaded circuits, and anything that poses a fire or shock risk, then tests circuits to confirm they perform as they should under load and fault conditions.

We've carried out thousands of these inspections across London and the South East, for landlords, homeowners, and commercial clients alike. In this article, we'll walk through each area an engineer examines, what the different classification codes mean, and what typically leads to a satisfactory or unsatisfactory result.

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How an EICR inspection is carried out

An EICR inspection follows a set process rather than a random poke around your consumer unit. The engineer starts with a visual inspection of the whole installation, then moves onto dead testing and live testing once the power's been safely isolated. Most domestic properties take between one and three hours, depending on the number of circuits and how accessible things like the loft or under-floor wiring are. Commercial premises with multiple distribution boards can take a full day or longer.

Visual inspection first

Before any testing begins, the engineer walks the property checking for obvious damage, incorrect cable types, missing covers, signs of overheating, and DIY work that doesn't meet current standards. This visual pass often reveals issues that testing alone wouldn't catch, like a cracked socket faceplate or cables run through a wall without proper protection.

Dead and live testing

Once the visual check is done, the engineer isolates the supply and runs a series of dead tests to check continuity, insulation resistance, and polarity across every circuit. With the power safely restored, live tests then confirm earth fault loop impedance and RCD trip times, which show how the system would behave during an actual fault.

An EICR combines what the engineer can see with what the tests actually prove, and neither on its own tells the full story.

Recording the findings

Every result gets logged against the relevant circuit, and any defect is noted with a classification code explaining its severity. This structured record is what eventually becomes your certificate, so the testing stage isn't just a formality, it's the evidence behind every conclusion in the final report.

What areas and components does an EICR check

Every EICR works through the same core components, though the exact number of circuits varies by property size. The consumer unit gets checked first, looking at the condition of the enclosure, whether RCD protection is fitted where required, and if breakers are correctly rated for the circuits they protect. Older units with rewireable fuses or plastic (rather than metal) enclosures often trigger observations simply because they no longer meet current standards, even if they're technically still working.

From there, the engineer works through the fixed wiring itself, checking cable condition, correct routing, and adequate protection where cables pass through joists or walls. Sockets, switches, and light fittings all get inspected and tested individually, along with the earthing and bonding arrangements that protect you if a fault develops. Poor earthing is one of the most common issues we find, particularly in properties with older plumbing or gas installations that were never properly bonded.

A single missing earth bond can undo the protection built into every other circuit in the property.

Beyond the obvious fittings, the inspection covers a few areas people often forget about:

• Bathroom and kitchen zones, where water proximity raises the risk and stricter rules apply

• Outdoor sockets and garden wiring, checked for weatherproofing and correct RCD protection

• Loft and under-floor cabling, inspected for damage from insulation, pests, or previous building work

• Extension leads and adapted circuits, flagged if they've become a permanent fix rather than a temporary one

Together, these checks build a full picture of the installation, not just the parts you can see from the hallway.

Understanding your EICR results and fault codes

Once testing wraps up, every observation gets a classification code that tells you how serious it is and how quickly it needs sorting. This is the part of the report most people skip straight to, and rightly so, because it determines whether your EICR comes back as satisfactory or unsatisfactory.

The four classification codes

Codes range from immediate danger through to simple recommendations, and understanding them helps you prioritise any remedial work.

Any C1 or C2 code results in an unsatisfactory report, meaning the installation doesn't meet current safety standards until the work is done. A report full of C3s can still pass as satisfactory, since these are recommendations rather than faults.

Why some issues outrank others

Severity depends on the actual risk, not the age of the component. A cracked switch cover might get a C3, while exposed live wiring in a similar spot gets a C1 because someone could get hurt right now. This is why two properties with similar wiring ages can come back with very different results.

The classification code matters more than the number of observations, one C1 outweighs a page full of C3s.

Remedial quotes should always reference the specific code and circuit, so you know exactly what's being fixed and why it was flagged in the first place.

Keeping your electrics safe and compliant

An EICR isn't a box-ticking exercise, it's a genuine check on whether your property's electrics will keep you, your tenants, or your staff safe. Knowing what an engineer looks at, from the consumer unit to earthing arrangements and everything tested in between, makes the resulting report far less intimidating when it lands in your inbox.

Whether you're a landlord due a renewal, a homeowner selling up, or a business covering health and safety obligations, the same principle applies: get the inspection done by someone qualified, act on any C1 or C2 codes promptly, and keep your certificate on file as proof of compliance.

If you need an EICR carried out anywhere in London or the South East, our engineers have the experience to get it right first time. Get a quote today and we'll sort a convenient time to visit.