PAT testing is the examination and testing of portable electrical appliances to ensure they're safe to use. Despite popular belief, PAT testing itself is not a legal requirement — but maintaining safe electrical equipment is.
When did you last test your electrical equipment?
Let's work out what you need to do.
What does PAT stand for?
PAT stands for Portable Appliance Testing.
Despite the name, it's not just about appliances you can carry around. "Portable" in this context means any equipment with a plug that connects to the mains electricity supply — from kettles and desk fans to photocopiers, vending machines, and fixed-position equipment.
The term "PAT testing" is slightly redundant since the "T" already stands for "Testing" — so saying "PAT Testing" is like saying "Portable Appliance Testing Testing". Nevertheless, this is the term everyone uses and understands.
What equipment needs PAT testing?
PAT testing applies to portable electrical equipment, which includes:
Class I equipment (earthed):
- Desktop computers and monitors
- Photocopiers and printers
- Power tools
- Kettles and coffee machines
- Microwave ovens
- Washing machines and tumble dryers
- Extension leads and power strips
Class II equipment (double insulated, no earth):
- Laptop and phone chargers
- Battery-operated equipment with charging bases
- Some power tools
- Vacuum cleaners (many models)
- DVD players and TVs (many models)
Class III equipment (low voltage):
- Equipment powered by transformers
- Equipment operating below 50V AC
Look for the double square symbol (⧈) on equipment nameplates — this indicates Class II double-insulated equipment. These items don't have an earth connection but rely on two layers of insulation for protection.
What doesn't need PAT testing?
- Fixed electrical installations (covered by fixed wire testing/EICR)
- Equipment that's never moved (wired directly into the building)
- Gas appliances
- Battery-powered equipment with no mains charging connection
- Equipment in domestic residential properties (though landlords should consider testing)
Legal requirements: the reality
Here's the truth that surprises many people: PAT testing is not a specific legal requirement.
There's no law that says "you must PAT test your equipment every 12 months" or even that PAT testing must be done at all.
What the law actually requires is that electrical equipment is maintained to prevent danger. The Electricity at Work Regulations 1989 state that "all systems shall at all times be of such construction as to prevent, so far as is reasonably practicable, danger."
What does this mean in practice?
You must:
- Keep electrical equipment in a safe condition
- Perform suitable maintenance
- Check equipment regularly enough to detect faults before they become dangerous
- Keep records demonstrating you've met these duties
PAT testing is one way — often the most practical way — of demonstrating compliance. But it's the outcome (safe equipment) that matters, not the process name.
Just because there's no specific "PAT testing law" doesn't mean you can ignore electrical safety. If someone is injured due to faulty electrical equipment you failed to maintain, you can be prosecuted under health and safety law, regardless of whether you "did PAT testing" or not.
Visual inspection vs electrical testing
PAT testing actually consists of two elements:
Visual inspection (essential for all equipment)
A thorough visual check looking for:
- Damaged plugs, sockets, or cables
- Damaged casing or covers
- Signs of overheating (burn marks, discoloration)
- Loose parts or screws
- Appropriate fuse rating
- Damaged or missing safety labels
- Inappropriate repairs or modifications
- Equipment used in unsuitable conditions
Visual inspection catches around 90% of faults that could cause danger. It should be done regularly by a competent person — often more frequently than formal testing.
Electrical testing (for higher-risk equipment)
Electrical tests using a PAT testing machine include:
- Earth continuity test — ensures the earth connection is sound (Class I equipment)
- Insulation resistance test — checks for current leakage
- Earth leakage test — measures leakage current during operation
- Polarity test — confirms wiring is correct
- Flash test — high-voltage insulation check (less common)
- Load/substitute leakage test — for Class II equipment
- Functional checks — verifying equipment operates correctly
Visual Inspection vs Electrical Testing
Visual Inspection Only
- •Quick and can be done by trained users
- •No specialist equipment needed
- •Catches most obvious faults
- •Can be done very frequently
- •Suitable for low-risk environments
- •Essentially free after training
Visual + Electrical Testing
Recommended- •More thorough safety assurance
- •Detects hidden electrical faults
- •Requires PAT testing equipment
- •Must be done by trained/competent person
- •Higher confidence for high-risk environments
- •Creates verifiable records
Bottom line: For most workplaces, a combination approach works best: frequent visual inspections by users, with periodic electrical testing based on equipment type and risk. Low-risk office equipment might only need electrical testing every 2-4 years, while high-risk construction tools need it much more frequently.
Testing frequencies: how often should you test?
There's no fixed legal answer — it depends on your risk assessment. However, the HSE and IET Code of Practice provide useful guidance:
Typical PAT Testing Frequencies
High-risk: harsh environment, frequent movement, high likelihood of damage
Medium-risk: equipment moved regularly, moderate working conditions
Equipment moved occasionally, stable environment
Low-risk: equipment rarely moved, protected environment
Test before bringing into service to establish baseline safety
Always test after any repair involving electrical components
Factors affecting test frequency
Increase testing frequency when:
- Equipment is used in harsh environments (construction sites, outdoors, wet conditions)
- Equipment is moved frequently
- Users are not trained to spot faults
- Equipment is available to the public
- There's a history of faults or damage
- Equipment is used by vulnerable people
You can reduce frequency when:
- Equipment is in a low-risk office environment
- Equipment stays in fixed positions
- Users are trained to report faults
- There's a good maintenance culture
- Historical testing shows few failures
Visual inspection should happen much more frequently than electrical testing. In many workplaces, users should visually check equipment before each use, with formal visual inspections monthly or quarterly, and electrical testing annually or less frequently based on risk.
Who can do PAT testing?
Anyone who is "competent" can perform PAT testing. There's no legal requirement for specific qualifications, but competence means:
For visual inspections:
- Understanding what to look for
- Training on common faults and hazards
- Ability to recognize damage
- Knowledge of when to remove equipment from service
Any employee can be trained to do basic visual inspections with a few hours of instruction.
For electrical testing:
- Understanding of electrical safety principles
- Training on how to use PAT testing equipment correctly
- Ability to interpret test results
- Knowledge of pass/fail criteria
- Understanding of different equipment classes
- Record keeping skills
Many electrical contractors and dedicated PAT testing companies offer testing services. Typical costs are £1-3 per item for basic testing, with mobile services visiting your premises. For large equipment inventories, training your own staff and purchasing equipment (£300-2000) may be more cost-effective.
Training and certification
While not legally required, training courses are available:
- City & Guilds 2377 (PAT Testing)
- City & Guilds 2377-22 (In-Service Inspection and Testing)
- IET Code of Practice awareness training
- Manufacturer-specific training for PAT testing equipment
These courses typically last 1-3 days and provide both theory and practical experience.
Pass, fail, and labelling
Test results
Equipment is classified after testing:
PASS — Equipment is safe to use
- Apply a pass label with test date and next test due date
- Return to service
- Record the pass result
FAIL — Equipment is unsafe
- Remove from service immediately
- Apply a fail label or physically mark as failed
- Disconnect and secure so it cannot be used
- Repair if economical, otherwise dispose of
- Record the failure and action taken
PAT testing labels
While not legally required, labels are best practice:
Pass labels typically show:
- Test date
- Next test due date
- Unique asset/serial number
- Tester name or company
Label colors (conventional, not legally defined):
- Green — Pass
- Red — Fail
- Orange/Yellow — Awaiting repair or retest
Some organizations use color-coded labels by year (e.g., blue for items tested, red for 2025) to make it obvious at a glance which equipment is overdue. This is particularly useful in large organizations with thousands of items.
Record keeping
You should maintain records of testing that include:
Equipment details:
- Description of equipment
- Manufacturer and model
- Unique identifier/asset number
- Location/department
- Equipment class
Test details:
- Date of inspection/test
- Type of inspection/test performed
- Test results (pass/fail)
- Measurements recorded (earth continuity, insulation resistance, etc.)
- Name of tester
- Next test due date
Fault and action records:
- Any defects found
- Action taken
- Repairs carried out
- Date returned to service or disposed of
Good record keeping demonstrates due diligence. If someone is injured and you're investigated, clear records showing regular testing and maintenance of electrical equipment will be crucial to your defense.
Digital vs paper records
Modern PAT testing equipment often includes:
- Barcode scanning for quick asset identification
- Bluetooth/WiFi connectivity to apps
- Automatic test result recording
- Cloud-based record storage
- Scheduled reminder systems for retesting
This can significantly reduce administrative burden compared to paper-based systems.
Common misconceptions
Office manager assumes all equipment needs annual testing
An office manager of a small company with 30 employees scheduled PAT testing for all equipment annually, costing around £300/year. This included computers that never moved and equipment in a low-risk office environment.
- ✗Testing frequency not based on risk assessment
- ✗Low-risk fixed equipment tested unnecessarily often
- ✗No visual inspection regime between formal tests
- ✗Following 'what everyone else does' rather than actual requirements
- ✗Money spent on testing could have been better used elsewhere
After understanding the regulations, the office implemented user visual checks, reduced formal PAT testing to every 2-3 years for fixed equipment, and invested savings in staff training and improved electrical safety culture.
PAT testing frequency should be based on risk assessment, not arbitrary timescales or 'industry standards'. Understanding the regulations saves money while maintaining safety.
Myth-busting
Myth 1: "PAT testing is a legal requirement"
- Reality: Maintaining safe electrical equipment is the requirement. PAT testing is one method of achieving this, but not the only one.
Myth 2: "All equipment must be tested every year"
- Reality: Testing frequency should be based on risk. Low-risk equipment might need testing every 4 years, high-risk equipment every 3 months.
Myth 3: "Only a qualified electrician can do PAT testing"
- Reality: Anyone competent can do PAT testing. Electricians have relevant knowledge, but competence can be gained through training.
Myth 4: "You need PAT testing to get insurance"
- Reality: While insurers care about electrical safety, there's no universal insurance requirement for PAT testing specifically. Requirements vary by insurer and policy.
Myth 5: "Portable appliance testing only covers things you can carry"
- Reality: "Portable" means anything with a plug, including fixed-position vending machines, photocopiers, and other equipment.
Myth 6: "New equipment doesn't need testing"
- Reality: While brand-new equipment from reputable suppliers is likely safe, you should visually inspect it and establish a baseline record. Equipment can be damaged in transit or storage.
Myth 7: "A PAT test sticker means equipment is safe until the next test date"
- Reality: Equipment should be visually checked regularly. A fault could develop any time after testing. Users should report visible damage immediately.
Risk assessment approach
Rather than blindly following testing schedules, take a risk-based approach:
Step 1: Categorize your equipment
Group equipment by:
- Type (IT, handheld tools, kitchen appliances, etc.)
- Usage (fixed position, moved daily, moved occasionally)
- Environment (office, construction site, outdoor, wet areas)
- User group (trained staff, public, vulnerable people)
Step 2: Assess the risk for each category
Consider:
- How likely is damage? (based on environment and handling)
- How severe could the consequences be? (user vulnerability, equipment power)
- What's the history of faults in this category?
Step 3: Determine testing regime
For each category, decide:
- Frequency of user visual checks (daily, weekly)
- Frequency of formal visual inspection (monthly, quarterly)
- Frequency of electrical testing (3 months to 4 years)
- Who will perform each type of check
Step 4: Document and review
- Record your decisions and reasoning
- Review the regime if circumstances change
- Check whether your regime is catching faults or whether equipment fails between tests
If you're finding no faults during testing, you might be testing too frequently (wasting resources) or your equipment is in a genuinely low-risk environment. If faults regularly emerge between tests, increase frequency or improve user checks.
Alternatives and complementary measures
PAT testing isn't the only way to maintain electrical safety:
User checks:
- Train users to visually check equipment before use
- Encourage reporting of faults
- Create a culture where people feel comfortable removing unsafe equipment from service
Planned maintenance:
- Replace equipment on a schedule before it becomes unsafe
- Keep equipment clean and well-maintained
- Store equipment appropriately
Purchase policies:
- Buy quality equipment from reputable suppliers
- Choose robust equipment suitable for the environment
- Avoid cheap, poorly-made products
Fixed wire testing (EICR):
- Test the building's electrical installation periodically
- Ensures sockets, circuits, and distribution boards are safe
- Typically every 5 years for commercial premises
RCD protection:
- Use residual current devices on circuits and portable RCDs
- Provides additional protection against electric shock
- Particularly important in wet environments or outdoor work
In-house vs Contracted PAT Testing
In-house Testing
- •Lower long-term cost for large inventories
- •Test on your schedule, no appointments needed
- •Staff gain competence in electrical safety
- •Immediate response to new equipment
- •Initial investment: £300-2000 for equipment
- •Ongoing: staff time and training
Contracted Service
Recommended- •No equipment investment needed
- •Expert competence guaranteed
- •Service provider has insurance
- •External verification of safety
- •Typically £1-3 per item
- •Minimal staff time required
Bottom line: For small inventories (under 100 items) or organizations without maintenance staff, contracting is usually most practical. For larger organizations with maintenance teams, in-house testing after appropriate training may be more cost-effective and flexible.
Frequently asked questions
No. There's no law specifically requiring PAT testing. However, the Electricity at Work Regulations 1989 require you to maintain electrical equipment in a safe condition. PAT testing is widely recognized as a good way to demonstrate compliance, but it's the safe condition that matters, not the testing label.
It depends on your risk assessment. The HSE provides guidance: construction equipment every 3 months, equipment that's regularly moved every 6-12 months, office equipment in fixed positions every 2-4 years. Visual inspections should happen much more frequently than electrical testing.
Yes, if you're competent. Competence means having sufficient knowledge, training, and experience. You don't need to be an electrician, but you need to understand electrical safety, how to use PAT testing equipment, and how to interpret results. Training courses are available and recommended.
You need to maintain safe electrical equipment. For a small, low-risk office, this might mean regular visual checks by staff, with formal electrical testing every 2-4 years for fixed equipment. The emphasis should be on risk-based maintenance rather than arbitrary testing schedules.
It must be removed from service immediately, labeled as failed, and either repaired by a competent person or disposed of safely. You should record what failed, why it failed, and what action was taken. Never allow failed equipment to be used.
For domestic tenancies, there's no legal requirement for landlords to PAT test appliances, though visual checks are sensible. For HMOs (Houses in Multiple Occupation) and commercial lettings, PAT testing is generally expected as part of electrical safety obligations. Always check your specific duties.
Commercial testing services typically charge £1-3 per item for basic testing, often with minimum charges or callout fees. Mobile services visit your premises. For large inventories, buying equipment (£300-2000) and training staff may be cheaper long-term. Always get quotes.
There's no legal 'test due date' in the first place, so there's no grace period. What matters is whether equipment is safe. If your risk assessment says equipment should be tested annually and it's overdue, you should test it promptly or remove it from service until tested.
Absolutely not. Equipment that has failed testing must be removed from service immediately. Using it creates a real risk of electric shock or fire. The cost of repair or replacement is always less than the cost of an injury or prosecution.
Next steps
If you're unsure about your electrical safety obligations, start with a risk assessment of your electrical equipment:
Electrical Safety in the Workplace →
For fixed electrical installations (wiring, sockets, distribution boards), you need periodic fixed wire testing:
Need help establishing a PAT testing regime or ensuring your electrical equipment is maintained properly? A qualified electrician or PAT testing specialist can assess your requirements and provide practical solutions for your situation.
Related articles:
- Electrical Safety in the Workplace
- Fixed Wire Testing (EICR)
- Who is Responsible for Electrical Safety?
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