An EICR inspects and tests your electrical installation, but it does not usually open up every socket, switch and light. BS 7671 leaves the size of that sample to the inspector, as long as the extent of the inspection and any limitations are agreed and written on the report. Long-standing IET guidance treats less than about 10% as too small, and the sample should grow when faults turn up. The bigger the sample, the more your report can tell you.
Key takeaways
- BS 7671 does not fix a percentage. It requires the extent of the inspection and any limitations to be agreed and recorded on the report.
- Guidance varies: long-standing IET guidance treats a sample under about 10% as too small, while Electrical Safety Roundtable guidance for rented homes in England asks for at least 20% of the accessories on each circuit.
- If the first items opened show faults, the sample should get bigger.
- The more limitations a report carries, the less it can tell you, and anything left out stays your responsibility.
- Under BS 7671 Amendment 4, only C1 and C2 make a report unsatisfactory. FI is now advisory, but landlords should still act on it.
Most people book an Electrical Installation Condition Report expecting a complete check of their wiring. In practice, how complete it is depends on how much of the installation the electrician actually opens up and looks at. That varies more than you might think, and it is the main reason two EICRs on similar homes can be so different in value.
What does an EICR inspect, and what does it test?
An EICR has two halves. The inspection is a careful look at everything that can be reached: the consumer unit, visible cables, sockets, switches, light fittings, and the earthing and bonding to your gas and water pipes. The testing uses instruments to measure what the eye cannot see, such as whether circuits are correctly earthed, whether insulation is breaking down, and whether your RCDs trip quickly enough to protect you.
Some things are not checked unless you agree otherwise. The standard limitations printed on the report say that cables hidden in walls, under floors, in roof spaces and inside trunking or conduit are not inspected. The latest model report also notes that no checks have been made for product recalls or safety alerts on equipment that forms part of your installation.
What does “sampling” mean on an EICR?
Opening every accessory in a typical home would add hours to the visit, so most inspections open up a sample: a selection of sockets, switches and fittings spread across every circuit and every floor, including the oldest parts of the house and anywhere that has clearly been altered. Inside those boxes the inspector checks the terminations, the condition of the insulation and the earth connection.
The report has to say how much was covered. BS 7671 requires the extent of the inspection and any limitations to be recorded, along with the reasons and the name of the person they were agreed with. The latest model report also asks the inspector to note where the sample was taken, and Electrical Safety First guidance recommends recording which items were opened, so the next inspection can look at different ones.
Is there a minimum percentage an electrician must check?
Not in law, and not in BS 7671 itself. The figures you will see mentioned come from guidance, and they do not all agree:
| Source | Applies to | What it says |
|---|---|---|
| BS 7671 (the wiring regulations) | All installations | No fixed percentage. The extent and any limitations must be agreed and recorded. |
| IET Guidance Note 3 (long-standing edition) | All installations | Sample size is the inspector’s call, but below about 10% is inadvisable. Increase it if faults are found. |
| Electrical Safety Roundtable (2020) | Rented homes in England | Test the whole installation, and open at least 20% of the accessories on each circuit. |
| Electrical Safety First Best Practice Guide 10 (2025) | Rented homes | A sufficient, representative sample. Suggested minimum: a switch and a light on each lighting circuit, and a socket on each socket circuit. |
The common thread is that the sample must be representative, recorded on the report, and made bigger when the first items reveal problems. As IET guidance puts it, poor results in a sample suggest that similar problems may exist elsewhere.
What can opening a socket or switch reveal?
A socket can look perfect from the front and still hide a problem behind the faceplate. Electrical Safety First’s guide to coding EICR observations lists defects such as:
- loose connections showing signs of overheating, or charring
- conductors clamped on their insulation instead of bare copper
- a socket with no earth connection
- incorrect polarity
- cable sheathing that stops short of the box, leaving the inner cores unprotected
- old insulation so brittle that it breaks away
- a “borrowed neutral”, where one circuit relies on the neutral of another
Each of these is classed as C2, potentially dangerous. Several of them, especially overheating, loose terminations and damaged insulation, can only be seen once the accessory is opened, which is why the size of the sample matters.
Why do limitations and small samples matter to you?
An EICR is only as useful as what it covers. Electrical Safety First’s Best Practice Guide 4 puts it plainly: the greater the limitations, the lower the value of the report. Its guide for landlords goes further on responsibility. The inspector is only liable for the parts of the installation stated as inspected and tested. The person who ordered the report stays responsible for everything else, including any parts they chose to leave out.
That is why a cheap, quick inspection can be a false economy. In 2022 the IET’s E&T magazine reported so-called drive-by inspections, with paperwork completed without anyone entering the property, and noted that an inspection in line with industry guidance needs around three hours on site for a small flat and about four for a typical three-bedroom house.
Nulectrics prices every EICR as a written estimate rather than a fixed fee, because the time it takes depends on the size of the property and how much of it we open up and inspect. We often find we sit at the higher end of what most inspections cover. For you, that means a report you can rely on, and lasting peace of mind that your electrics are sound.
What do landlords need to know in 2026?
In England, the Electrical Safety Standards in the Private Rented Sector Regulations 2020 require the installation to be inspected and tested by a qualified person at least every five years, or sooner if the report says so. The report must go to tenants within 28 days, and to the council within 7 days if it asks. Any remedial or further investigative work the report requires must be completed within 28 days. Since 1 November 2025 the maximum penalty for a breach is £40,000, and the rules have been extended to social housing.
Amendment 4 changed how one code works. An FI, for further investigation, is now advisory and does not on its own make a report unsatisfactory; only C1 and C2 do, as NICEIC explains. Government guidance for landlords, written before the change, still says further investigation must be carried out within 28 days, so the safe course is to treat an FI as work to complete.
In Wales, an electrical condition report must be renewed at least every five years, with a copy given to the contract-holder within 14 days of occupation. In Scotland, the Repairing Standard also requires an EICR at least every five years.
How can you tell whether your EICR was thorough?
- Read the extent and limitations section. It should say what was covered, what was not, why, and who agreed it.
- Look for LIM and N/V in the schedule. LIM means a limitation and N/V means not verified. Ask about any you were not expecting.
- Check the schedule of test results. It should list the circuits tested. If some are missing, ask why.
- Check who signed it. The inspector should be named and belong to a registered scheme such as NICEIC or NAPIT.
- Look for specific observations. Electrical Safety First’s guidance says vague notes such as “poor” or “recommend a rewire” are not acceptable.
- Think about the time on site. An average home takes around three to four hours.
If you need an EICR in Chippenham, Wiltshire, Bath or Bristol, our EICR service starts with a free, no-obligation written estimate. Call 07530 526 390 or send us your details and we will talk you through what the inspection will cover.
Service areas: Nulectrics is based in Chippenham, Wiltshire. We cover domestic work across Chippenham, Corsham, Calne, Melksham, Devizes, Trowbridge, Bath and the surrounding area, and commercial work UK-Nationwide.