What is Fixed Wire Testing?

Fixed wire testing — also known as an Electrical Installation Condition Report (EICR) or periodic inspection — checks the safety of the permanent electrical wiring, circuits, and systems in your building. It identifies hazards, deterioration, and non-compliance with safety standards that could lead to electric shock or fire.

What is fixed wire testing?

Fixed wire testing is the inspection and testing of the permanent electrical wiring and systems built into a property — the cables, circuits, consumer unit (fuse box), and electrical accessories that are fixed in place.

It's formally called an Electrical Installation Condition Report (EICR), though you might also hear it referred to as:

• Periodic inspection
• Fixed wiring test
• Electrical safety certificate
• Hard-wire testing

What does fixed wire testing cover?

The inspection examines:

Fixed wiring and cables:

• Cables running through walls, under floors, in ceilings, and in trunking
• Main incoming supply cables
• Meter tails and service head connections
• Distribution cables throughout the building

Consumer unit (fuse box):

• Circuit breakers and protective devices
• RCDs (Residual Current Devices)
• Main switch and isolators
• Condition of the unit and internal connections

Electrical circuits:

• Lighting circuits
• Power socket circuits
• Cooker and immersion heater circuits
• Dedicated circuits (showers, electric vehicle charging, etc.)

Safety provisions:

• Earthing arrangements
• Bonding to water, gas, and other services
• Earth fault protection
• Surge protection (where required)

Fixed electrical accessories:

• Light switches and dimmers
• Socket outlets
• Fused connection units
• Ceiling roses and lamp holders
• Cooker control units
• Immersion heater switches

What fixed wire testing doesn't cover

Portable appliances:

• Equipment with plugs (kettles, computers, tools)
• These need PAT testing instead

Gas or water systems:

• Only the electrical bonding to these systems is checked

Telecommunications and data cabling:

• Phone lines, network cables, TV aerials
• Unless they have implications for electrical safety

How fixed wire testing differs from PAT testing

People often confuse these two types of electrical testing. They're both about safety, but they test completely different things.

Think of it this way:

• Fixed wire testing checks everything from the meter to the sockets
• PAT testing checks everything you plug into those sockets

What's involved in a fixed wire test?

A fixed wire test is carried out by a qualified electrician and typically takes 2-4 hours for a standard domestic property, or longer for commercial buildings with more circuits.

Before the inspection

Preparation needed:

• The electrician needs access to all areas (including loft, underfloor spaces if accessible)
• Consumer unit must be accessible
• Some circuits will be switched off during testing
• You'll need to save work, turn off computers, and be prepared for power interruptions
• Inform the electrician about any critical equipment that must not lose power

Visual inspection

The electrician will examine:

• Condition of cables and accessories for damage or deterioration
• Consumer unit for signs of overheating, damage, or outdated components
• Correct installation methods and workmanship
• Whether circuits appear overloaded
• DIY or non-compliant electrical work
• Adequacy of earthing and bonding
• Labelling and documentation

Electrical testing

The electrician uses specialist test equipment to measure:

Continuity testing:

• Ensures protective conductors (earth wires) are properly connected throughout
• Checks that the circuit wiring is continuous with no breaks
• Verifies bonding connections are effective

Insulation resistance testing:

• Tests that cables and wiring insulation is intact
• Detects deterioration or damage that could cause shock or fire
• Identifies moisture ingress or cable degradation

Polarity testing:

• Confirms live and neutral are correctly connected
• Checks that switches are wired to break the live conductor
• Verifies socket outlets are wired correctly

Earth fault loop impedance testing:

• Measures the path electricity takes during a fault
• Ensures protective devices will operate quickly enough
• Critical for safety — determines if earth protection will work

RCD testing:

• Tests that RCDs (trip switches) will operate within safe time limits
• Checks disconnection time under fault conditions
• Verifies sensitivity is correct

Circuit loading assessment:

• Checks circuits aren't dangerously overloaded
• Assesses whether cable sizes are appropriate for loads
• Identifies circuits operating near capacity

After the inspection

The electrician will:

• Provide an EICR certificate detailing the findings
• Explain any defects found and their significance
• Give you a schedule of test results with all measurements
• Classify any problems with codes (C1, C2, C3, or FI)
• Mark the result as satisfactory or unsatisfactory
• Recommend when the next inspection should take place

Understanding test results

Every defect or observation is given a classification code that indicates its seriousness.

C1 — Danger present

Immediate risk. Do not use until fixed.

A C1 code means there's a dangerous condition that poses an immediate risk of electric shock or fire right now.

Examples:

• Live electrical parts that can be touched
• Complete absence of earthing
• Severely damaged cables with live parts exposed
• Missing RCD protection where water is present
• Protective devices bypassed or disconnected

What to do: The circuit or installation should not be used. The electrician may isolate the dangerous circuit immediately. Get it repaired urgently before using the affected circuits.

C2 — Potentially dangerous

Urgent action required.

A C2 code means the defect is potentially dangerous. It's not presenting immediate risk now, but could become dangerous if a fault occurs or conditions change.

Examples:

• Inadequate earthing or bonding
• Wrong size or type of protective device
• Insufficient shock protection
• Lack of RCD protection on socket circuits
• Old wiring in poor condition
• Overloaded circuits

What to do: Arrange for repairs as soon as possible. For landlords, this must be within 28 days.

C3 — Improvement recommended

Not dangerous, but improvement would be beneficial.

A C3 code means something doesn't meet current best practice standards, but isn't actually dangerous.

Examples:

• Old wiring in good condition but not to latest standards
• Missing circuit labelling
• Lack of surge protection (now recommended)
• Recommendations to upgrade when next renovating

What to do: Consider addressing during planned maintenance. Not urgent. May improve safety or bring installation up to current standards.

FI — Further investigation required

More investigation needed urgently.

An FI code means the electrician couldn't fully inspect or test something, and further investigation is required.

Examples:

• Areas not accessible during inspection
• Parts of installation that couldn't be fully tested
• Signs of a problem that needs specialist investigation
• Underground cables or concealed wiring with suspected faults

What to do: Arrange for the additional investigation promptly to determine if remedial work is needed.

Testing frequency requirements

How often you need fixed wire testing depends on the type of property and its use.

Rental properties (landlords)

Private rented residential properties in England:

• Every 5 years maximum
• Before a new tenancy begins (if more than 5 years since last test)
• Certificate must be provided to tenants within 28 days
• Mandatory under Electrical Safety Standards in the Private Rented Sector Regulations 2020

Scotland:

• Every 5 years for private rented properties
• Before each new tenancy
• Similar requirements under separate Scottish regulations

Wales:

• Every 5 years for private rented properties
• Requirements align with England

Northern Ireland:

• Not currently mandatory for private landlords
• Strongly recommended for safety and due diligence

Houses in Multiple Occupation (HMOs)

Licensed HMOs:

• Every 5 years minimum
• Often required more frequently (check your license conditions)
• Local authorities may specify shorter intervals
• Usually required before license is granted or renewed

Commercial and workplace premises

The Electricity at Work Regulations 1989 require electrical systems to be maintained to prevent danger. While there's no specific frequency mandated by law, guidance recommends:

Offices and shops:

• Every 5 years

Commercial kitchens and light industrial:

• Every 3 years

Industrial premises:

• Every 3 years

Environments with high risk (moisture, heat, vibration):

• Annually or more frequently

Leisure and entertainment venues:

• Every 3 years

Petrol stations and car washes:

• Annually

Care homes and healthcare premises

Care homes and nursing homes:

• Every 5 years minimum
• Often more frequently due to CQC expectations
• Some facilities test every 3 years

Hospitals and medical facilities:

• Every 3-5 years depending on the area
• Critical areas may need annual testing

Schools and educational buildings:

• Every 5 years recommended
• DfE guidance supports regular testing
• Science labs may need more frequent inspection

Places of worship and community buildings

Churches, temples, mosques:

• Every 5 years recommended
• More frequently if building is heavily used or hired out
• Important for insurance purposes

Community halls and village halls:

• Every 5 years recommended
• May be required by insurance or lease conditions
• More frequent if hired to public

Owner-occupied homes

Not legally required, but recommended:

• Every 10 years for owner-occupied homes
• When buying a property (especially older ones)
• Before selling (to identify issues that could affect sale)
• After major renovations or building work
• If you've had electrical problems

Who can perform fixed wire testing?

Fixed wire testing must be carried out by a qualified and competent electrician. This is more specialized than basic electrical installation work.

Qualifications needed

The electrician should have:

Core electrical qualifications:

• Level 3 electrical installation qualification (e.g., City & Guilds 2357)
• Knowledge of BS 7671 (18th Edition) IET Wiring Regulations
• Understanding of electrical principles and safety

Inspection and testing qualifications:

• City & Guilds 2391 (Inspection and Testing) or equivalent
• City & Guilds 2394-01 (Initial Verification)
• City & Guilds 2395-01 (Periodic Inspection)
• Practical experience in inspection and testing

Up-to-date knowledge:

• Current with latest edition of BS 7671
• Continuing professional development
• Regular testing experience

Competent person schemes

While not legally required, using an electrician registered with a recognized competent person scheme provides assurance:

Major schemes:

• NICEIC (National Inspection Council for Electrical Installation Contracting)
• NAPIT (National Association of Professional Inspectors and Testers)
• ELECSA (Electrical Safety Certification Scheme)
• Stroma Certification
• NAIC (National Association of Inspectors and Certification)

These schemes:

• Assess members' technical competence regularly
• Require appropriate qualifications and insurance
• Investigate complaints
• Provide consumer protection
• Maintain standards

Questions to ask when choosing an electrician

Before booking:

• Are you qualified to carry out EICRs?
• What qualifications do you hold? (Look for 2391/2394/2395)
• Are you registered with a competent person scheme? (NICEIC, NAPIT, etc.)
• Do you have public liability and professional indemnity insurance?
• Can you provide references or examples of recent EICRs?
• How long will the inspection take?
• What's included in your quoted price?
• Will you explain the findings and provide advice on any remedial work?

What to expect from the service

A professional electrician will:

• Arrive with appropriate testing equipment
• Provide identification and proof of qualifications if asked
• Explain what they'll be doing and how long it will take
• Ask questions about the age of installation and any known issues
• Request access to all necessary areas
• Conduct thorough visual inspection and testing
• Explain findings clearly before leaving
• Provide detailed EICR certificate and schedule of test results
• Give clear guidance on any remedial work needed

Cost of fixed wire testing

Costs vary depending on property size, location, and complexity of the electrical installation.

Typical prices (2024):

• 1-2 bedroom flat: £120-180
• 3 bedroom house: £150-250
• 4-5 bedroom house: £200-350
• HMO or large property: £300-500+
• Commercial premises: £200-800+ depending on size and complexity

Factors affecting cost:

• Number of circuits (more circuits = longer testing time)
• Property size and layout
• Accessibility of consumer unit and wiring
• Location (London typically more expensive)
• Electrician's rates and experience
• Whether scheduling is urgent

What's included:

• Complete visual inspection
• Electrical testing of all circuits
• EICR certificate
• Schedule of test results
• Classification of defects
• Recommendations for remedial work
• Advice on next inspection date

Not usually included:

• Any remedial work identified
• Repeat inspection after repairs
• Moving furniture to access sockets or areas
• Accessing areas that require construction work to reach

What happens if you fail the test?

An unsatisfactory EICR doesn't mean your property is condemned. It's common, especially in older properties. Here's what to do:

Step 1: Understand what's wrong

Read the report carefully. The electrician should have explained the issues, but if anything's unclear:

• Ask the electrician to clarify
• Understand which codes are present (C1, C2, C3, or FI)
• Check which circuits or areas are affected
• Find out what remedial work is needed

Step 2: Prioritize the work

Immediate priority (C1 defects):

• These represent immediate danger
• Do not use the affected circuit until repaired
• The electrician may have isolated it already
• Get emergency repairs if necessary

Urgent priority (C2 defects):

• Potentially dangerous — must be fixed
• Landlords must complete within 28 days
• Get quotes and schedule work promptly

Lower priority (C3 defects):

• Improvements recommended but not urgent
• Consider addressing during planned maintenance
• May improve safety or future-proof installation

Investigation needed (FI codes):

• Arrange further investigation promptly
• May reveal issues that need urgent attention

Step 3: Get the work done

Options:

• The electrician who did the EICR can usually quote for remedial work
• You can get competitive quotes from other qualified electricians
• Ensure whoever does the work is competent and provides certification
• Keep all invoices and certificates

Types of certification you'll receive:

• Electrical Installation Certificate (EIC) — for new circuits or major work
• Minor Electrical Installation Works Certificate (MEIWC) — for smaller repairs
• Updated EICR — showing defects are now cleared (if follow-up inspection arranged)

Step 4: Provide documentation

For landlords:

• Provide copy of EICR to tenant within 28 days of inspection
• Complete C1 and C2 work within 28 days
• Provide copy of remedial certificate to tenant within 28 days of completion
• Keep copies for your records and for local authority if requested
• Failure to comply can result in fines up to £30,000

For other property owners:

• Keep certificate safe for future reference
• Provide to insurers if requested
• Include with property information when selling
• Make available for regulatory inspections if applicable

When is fixed wire testing required?

Mandatory requirements

England — private rental properties:

• Required by law since June 2020
• Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020
• Every 5 years maximum
• Before new tenancies if more than 5 years since last test
• Penalties up to £30,000 for non-compliance

Scotland — private rental properties:

• Required under similar Scottish regulations
• Every 5 years
• Before each new tenancy

Wales — private rental properties:

• Required under Welsh regulations
• Every 5 years
• Before each new tenancy

HMO licensing:

• Required as condition of license across UK
• Frequency specified in license (usually every 5 years)
• Must be current for license to be valid

Regulatory expectations

Workplaces:

• Electricity at Work Regulations 1989 require systems be maintained to prevent danger
• Fixed wire testing is the recognized method of demonstrating compliance
• Frequency based on environment (3-5 years typical)

Care homes:

• CQC expects regular electrical safety testing
• Usually 5 years, sometimes 3 years for higher-risk environments

Schools:

• Not specifically mandated but expected by local authorities and DfE
• Every 5 years recommended

Public buildings:

• Often required by insurance
• Expected for buildings license or regulatory approval
• Demonstrates due diligence

Voluntary but recommended

Owner-occupied homes:

• When buying a property
• Every 10 years as good practice
• Before selling
• After renovations or electrical work
• If experiencing electrical problems

Commercial property owners:

• Demonstrates duty of care
• Required by many insurance policies
• Good practice for asset management
• Protects against liability

Common problems found during fixed wire testing

Understanding what electricians commonly find helps you know what to expect and how to maintain your installation between tests.

Issues with consumer units

Old fuse boxes:

• Outdated rewireable fuses instead of circuit breakers
• No RCD protection
• Insufficient capacity for modern electrical loads
• Recommendation: Replace with modern consumer unit

Missing or inadequate RCD protection:

• Socket circuits without RCD protection (now required)
• No time-delay RCDs where needed
• RCDs that don't operate correctly
• Common C2 code requiring urgent attention

Damaged or deteriorated consumer units:

• Signs of overheating or burning
• Damaged internal connections
• Corrosion or water damage
• Immediate danger — C1 code

Wiring problems

Old wiring:

• Pre-1960s rubber or fabric-insulated cables
• Degraded insulation that's become brittle
• Wiring that's been in place for 40+ years
• May need complete rewire

Inadequate circuit capacity:

• Too many devices on one circuit
• Cable sizes too small for the load
• Overloaded circuits showing signs of stress

Damaged cables:

• Cables run incorrectly (e.g., through sharp edges)
• Mechanical damage from drilling or building work
• Rodent damage
• Heat damage from poorly ventilated spaces

Earthing and bonding issues

Missing or inadequate earthing:

• No proper earth connection
• Earth conductor too small
• Disconnected or corroded earth
• Very common C2 code

Missing main bonding:

• No bonding to gas and water services
• Insufficient bonding conductor size
• Bonding disconnected during renovations
• Required to prevent shock from metalwork

Missing supplementary bonding:

• No bonding in bathrooms (where still required)
• Missing bonding in areas with water and electrical equipment
• Bonding removed during renovations and not reinstated

DIY and non-compliant work

Unsafe DIY electrical work:

• Work not complying with BS 7671
• Inappropriate cable types or methods
• Dangerous connections
• Very common finding in older properties

Uncertified alterations:

• Extensions or new circuits without certification
• Work that should have been notified to Building Control
• Non-compliant installation methods

Socket and accessory problems

Damaged accessories:

• Cracked sockets or switches
• Burn marks from overheating
• Loose connections causing arcing
• Missing face plates

Wrong locations:

• Sockets too close to water sources
• Switches in bathrooms that don't comply
• Accessories damaged by location

Maintaining your electrical installation between tests

Fixed wire testing is a snapshot at one point in time. Between tests, you should maintain your installation to keep it safe.

Regular visual checks

Monthly or quarterly:

• Check consumer unit for signs of overheating, unusual smells, or damage
• Look for damaged or deteriorated sockets, switches, and cables
• Check nothing is loose or making unusual sounds
• Look for signs of dampness affecting electrical equipment

User awareness

Encourage occupants to:

• Report any electrical problems immediately
• Not overload sockets with adapters and extensions
• Switch off and unplug equipment that smells, sparks, or behaves unusually
• Report flickering lights or frequently tripping circuits

RCD testing

Test every 3 months:

• Press the test button on each RCD in your consumer unit
• The RCD should trip immediately
• If it doesn't trip, or is slow to trip, contact an electrician
• This is specified by regulations and manufacturers

When to call an electrician between tests

Get professional help if you notice:

• RCD or circuit breakers tripping frequently
• Burning smells from sockets, switches, or consumer unit
• Scorch marks on sockets or switches
• Flickering lights (not just one bulb)
• Shocks from appliances or electrical fittings
• Damage to cables, sockets, or switches
• Old wiring showing signs of deterioration
• Consumer unit getting hot

After any electrical work

Following installation or repairs:

• Ensure you receive proper certification (EIC or MEIWC)
• Check work has been notified to Building Control if required
• Keep certificates safe with your EICR
• If significant work is done, consider whether your EICR needs updating

Frequently asked questions

Next steps

If you're a landlord, understand your full electrical safety responsibilities:

Landlord electrical safety requirements

To understand the classification codes on your EICR report:

EICR codes explained

To learn about testing portable electrical equipment:

What is PAT Testing?

Related articles:

• What is an EICR?
• PAT Testing
• Landlord Electrical Safety Requirements
• Understanding EICR Codes

Useful tools:

• Compliance Checker
• Electrical Safety Self-Check