Is fixed wire testing mandatory?

Yes, fixed wire testing is mandatory. On 1 January 2019 a new standard of wiring regulations was introduced. This is the 18th edition and is known as BS7671 IET. These regulations are what your electronics are measured against during fixed wire testing.

At a minimum, fixed wire testing should be conducted every 5 years. This applies to commercial, educational, retail, and office environments. Varying environments may require more regular testing to comply with legislation. This is due to factors such as the use and operation of the building, alongside other factors.

What is it?

It is a test to ensure that all of the electrical components within a building are safe to operate and fit within electrical guidelines. The test will be performed by a couple of engineers in your building. The engineers will run some checks on the varying distribution boards within your electrical system. This will mean that individual circuits need isolating for a small time.

Once the fixed wire testing is finished, you will be issued with an Electrical Installation Condition Report, also known as an EICR. This will give you a written record of observations levied against their level of risk. They are being highlighted by the engineer as something that needs fixing to ensure your safety.

Following an unsatisfactory EICR you do not need to get a complete second fixed wire test. You should request an engineer to come out and check your repairs. You will need to be issued with a certificate to prove that the necessary changes have been made. This will either be an Electrical Installation Certificate or a Minor Works Certificate and should be kept with the original EICR.

What are the codes and what do they mean?


C1 means ‘danger present, risk of injury, and immediate remedial action is required’. It is a severe threat to the health and safety of individuals in your building and you must move to

neutralize the danger immediately.

Examples of C1 issues are damage causing electrics to be exposed, removed maintenance panels, and incorrect polarity. Incorrect polarity is dangerous as it can allow non-live conductive parts of the system to become live, which could potentially be dangerous.

You will be made aware of the danger both verbally and in written form, if you are the owner of the building. The circuit may be deactivated until the issue is resolved.


This is less severe than a C1 notice but is an issue that still needs to be addressed quickly. The description is ‘potentially dangerous – urgent remedial action required’. It is not necessarily an immediate danger, but has clear potential to develop into one.

The phrasing is used to indicate the potential risk of injury if a chain of event occurs that leads to the area of electrics becoming live. This can cause unexpected exposure to live electrical currents and can potentially be very dangerous to workers.


This is a much softer classification and just suggests that improvements are recommended. It is used when electronics do not comply with the most recent (18th version) of the wiring regulations. In these cases, there is not a danger present, but the writing needs updating to remain compliant.


This means that further investigations are required without any delay. This is used when the investigating engineer has noticed something that is not correct but cannot identify why. If there are multiple circuits rated as FI, this can cause your EICR to be deemed unsatisfactory.

Why is it important?

If the electrical wires within a building are not regularly tested to ensure their safety, there is the potential for malfunction. Depending on what is damaged, there could be a considerable amount of danger to the inhabitants of the building. It is vital to perform fixed wire testing regularly to prevent accidents happening.

What are the legal requirements?

This is covered by the Health and Safety Executive (HSE). They are a government body whose purpose is to ensure health and safety law is followed correctly. They oversee the design, use, and maintenance of electrical systems.

The laws that have an impact upon fixed wire testing are: Health & Safety at Work Act 1974, Management of Health & Safety at Work Regulations 1999, Electricity at Work Regulations 1989, and Workplace (Health, Safety, and Welfare) Regulations 1992

These laws apply to all electronics in the workplace and state that it is the responsibility of the employer to keep themselves, and their employees, safe.

How often does this need completing?

We have compiled a list of some common building types and the frequency at which fixed wire testing must be carried out. This varies depending on building purposes.

Buildings with high exposure to temperature extremes, moisture, and dust will need testing more frequently. If the general public comes into the building regularly it will be classed as a higher risk and will require more regular testing.

Building type

Routine check timeframe

Minimum testing frequency
General housing Not applicable Upon change of occupancy, or every 10 years
Rented housing and flats 1 year Upon change of occupancy, or every 5 years
HMOs and halls of residence 1 year Upon change of occupancy, or every 5 years
Educational buildings 6 months 5 years
Industrial buildings 1 year 3 years
Commercial buildings 1 year Upon change of occupancy, or every 5 years
Offices, shops, and laboratories 1 year 5 years
General areas of hospitals and medical clinics 1 year 5 years
Surgical areas of hospitals and medical clinics 6 months 1 year
Cinemas 1 year 1-3 years
Churches 1 year 5 years
Leisure centres (not pools) 1 year 3 years
Areas of public entertainment i.e. theatres 1 year 3 years
Restaurants, pubs, and hotels 1 year 5 years
Community centres 1 year 5 years
Swimming pools 4 months 1 year
Caravans 1 year 3 years
Caravan parks 6 months 1 year
Fire alarms Daily or weekly 1 year
Petrol stations 1 year 1 year
Construction sites 3 months 3 months

Are you looking to arrange a fixed wire test?

AMS Solutions are happy to provide Fixed Wire Testing reports to large and complex premises including:

  • Hotels
  • Schools/Colleges/Universities
  • Manufacturing and industrial premises
  • Large commercial premises
  • and many more

Are you due to have a fixed wire test carried out soon and are based in the North-West? Contact our team today for information on how we can help!


Is fixed wire testing mandatory?


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