PAT Testing Explained: A Practical Guide for Electricians and Landlords

Portable Appliance Testing (PAT testing) is one of the most misunderstood obligations in the UK electrical industry. Some think it's a legal requirement for every business. Others think it's unnecessary box-ticking. The truth, as is often the case, sits somewhere in between — and getting it right matters both for safety and for avoiding liability.

This guide cuts through the confusion. Whether you're a qualified electrician looking to add PAT testing to your service offering, or a landlord trying to understand your obligations, here's what you actually need to know.

What Is PAT Testing?

PAT testing is a process of examining electrical appliances and equipment to ensure they are safe to use. It involves a combination of visual inspection and electrical testing using a PAT tester — a specialist instrument that checks for faults in insulation, earth continuity, and other electrical safety parameters.

"Portable" in this context refers to anything that is plugged into a socket via a mains lead — not just items you'd carry around. This includes desktop computers, electric drills, kettles, floor lamps, extension leads, and even some fixed appliances with a plug. Items hardwired into the electrical installation are covered by fixed wiring inspections (EICR), not PAT testing.

Is PAT Testing a Legal Requirement?

Strictly speaking, PAT testing itself is not a legal requirement under any UK legislation. What is a legal requirement is that electrical equipment is maintained in a safe condition. The Electricity at Work Regulations 1989 requires employers to ensure all electrical systems (which includes appliances) are maintained to prevent danger. How they demonstrate that maintenance is their choice — and PAT testing is the most widely accepted method.

The relevant legislation includes:

• Electricity at Work Regulations 1989 — duty to maintain electrical equipment to prevent danger
• Health and Safety at Work Act 1974 — general duty of care for employers
• Provision and Use of Work Equipment Regulations 1998 (PUWER) — equipment must be suitable and maintained
• Management of Health and Safety at Work Regulations 1999 — risk assessment requirement

The HSE's own guidance is clear: "The law simply requires that electrical equipment is maintained in order to prevent danger. It does not say how this should be done or how often." A risk-based approach is perfectly acceptable, and for low-risk environments with new equipment, formal PAT testing intervals can be quite long.

Who Needs PAT Testing?

Any organisation where employees use electrical equipment at work should have a PAT testing programme in place. This includes:

• Offices, shops, and commercial premises
• Construction sites and workshops
• Schools, hospitals, and care homes
• Rental properties with electrical appliances provided by the landlord
• Self-employed individuals with business equipment

For domestic settings, PAT testing is not required by law unless it's a rental property with landlord-supplied appliances, or a home used as a workplace.

Landlords and HMOs

Landlords providing electrical appliances (white goods, electric fires, etc.) are advised to have them PAT tested before tenancy and periodically thereafter. For Houses in Multiple Occupation (HMOs), this is strongly recommended as part of the overall electrical safety regime. While the Electrical Safety Standards in the Private Rented Sector (England) Regulations 2020 focus on fixed wiring (EICR), PAT testing of appliances remains best practice.

Who Can Carry Out PAT Testing?

There is no legal requirement for PAT testing to be carried out by a qualified electrician. The requirement is for the person to be "competent" — meaning they have sufficient knowledge, experience, and training to carry out the task safely and correctly.

In practice, there are different levels of PAT tester:

• Trained operative — someone who has completed a PAT testing course (typically 1–3 days) and can use a PAT tester correctly
• Electrician or electrical engineer — can interpret results more deeply, deal with borderline cases, and advise on remedial action
• Responsible person — for very small businesses with low-risk environments, the employer themselves can carry out visual-only checks

For construction sites and high-risk environments, a qualified electrician is strongly recommended. For office environments, a trained operative is typically sufficient.

The PAT Testing Process

A full PAT test consists of two stages:

Stage 1: Visual Inspection

This is often overlooked but is arguably the most important part. The majority of faults are identified visually, not electrically. Check for:

• Damage to the plug (cracked casing, bent pins, scorch marks)
• Damage to the mains cable (cuts, fraying, kinking, wear at the entry point)
• The cable not being properly secured at the plug or appliance
• Signs of overheating or burn marks on the plug or socket area
• Damage to the appliance casing (cracks, missing covers)
• Evidence of unofficial repairs (insulation tape, bypassed fuses)
• Incorrect fuse rating (check against appliance wattage)
• The cable not being the right type for the application (e.g., light-duty cable on a heavy-duty tool)

Any item that fails visual inspection should be taken out of service immediately, regardless of electrical test results.

Stage 2: Electrical Testing

The electrical tests performed depend on the class of the appliance:

Class I appliances (earthed equipment — most power tools, computers, kitchen appliances):

• Earth continuity test — checks the earth conductor is intact and provides a low-resistance path to earth. Pass limit: typically ≤0.1Ω for cables up to 5m, increasing with length
• Insulation resistance test — checks the insulation between live conductors and earth. Pass limit: ≥1MΩ at 500V DC
• Substitute/lead leakage test (optional) — more representative of in-use conditions

Class II appliances (double-insulated — most hand tools, many IT equipment items):

• Insulation resistance test — typically between live conductors and any accessible metalwork. Pass limit: ≥2MΩ at 500V DC
• No earth continuity test (no earth in a Class II appliance)

Extension leads are tested as Class I items and also undergo a polarity check. IT equipment often requires a lower test voltage (250V) to avoid damaging sensitive components — check the manufacturer's guidance.

PAT Test Pass and Fail

A PAT tester will give a pass or fail result based on preset thresholds. Pass means the appliance is electrically safe at the time of testing. Fail means it should be taken out of service.

Pass and fail labels are then applied to the appliance, typically showing:

• Pass/Fail status
• Date of test
• Next test due date
• Tester's ID or company name

The label is not proof of safety in perpetuity — it's a record that the item was safe when tested. A failed appliance must be removed from service, repaired by a competent person, re-tested, and only returned to service once it passes.

Testing Frequencies

The IET Code of Practice for In-Service Inspection and Testing of Electrical Equipment (4th Edition) provides guidance on testing intervals. These are recommendations, not legal requirements, and should be adjusted based on risk assessment:

Construction sites have the shortest intervals because equipment is subjected to harsh conditions — dust, moisture, physical impact, and repeated use. Office equipment in a stable environment can go much longer between formal tests.

Equipment You'll Need

To carry out PAT testing properly, you'll need:

• PAT tester — quality units like the Megger PAT4 or Seaward Primetest perform all required tests and generate records automatically
• Pass/fail labels — typically self-adhesive, in green (pass) and red (fail)
• Test leads and adaptors — for testing different plug types
• Record-keeping software or register — a paper register is acceptable but software makes audits easier
• Screwdrivers — for checking plug wiring on suspect items

For electricians adding PAT testing to their service portfolio, a good-quality PAT tester with automatic sequence testing and downloadable records is essential. The time saved on data entry quickly justifies the premium.

Record Keeping

Maintaining records is not a legal requirement but is strongly recommended. Records provide evidence of compliance, help schedule future tests, and are invaluable if there is ever an insurance claim or accident investigation.

A PAT testing register should include:

• Description of the appliance
• Make, model, and serial number (where available)
• Asset number (useful for large inventories)
• Location
• Date of test
• Visual inspection result
• Earth continuity result (if applicable)
• Insulation resistance result
• Overall pass/fail
• Next test due date
• Tester's name

For large premises, an asset management approach — numbering each item and logging tests against the asset number — is far more manageable than relying on labels alone.

Common Misconceptions

"Everything needs testing every year"

This is false. Annual testing is appropriate for higher-risk environments like rental accommodation with provided appliances, or catering equipment. Office equipment may only need testing every two to four years. Blanket annual testing of everything is an expensive overcompliance that the IET guidance doesn't support.

"Only qualified electricians can do PAT testing"

Also false. Competence is required, not formal electrical qualifications. A trained PAT tester who has completed a recognised course can legally carry out testing. That said, for fault diagnosis and remedial work, an electrician is needed.

"A PAT pass means the appliance is safe"

A PAT test tells you the appliance was electrically safe at the time of testing. It doesn't account for mechanical failures, misuse, or faults that develop after testing. User awareness and visual checks between formal PAT tests are important.

"New equipment doesn't need PAT testing"

New equipment should be visually inspected before first use, but formal electrical testing is generally not required. The risk of a fault in new, properly manufactured equipment is low. However, equipment bought second-hand or from unknown sources should be tested before use.

PAT Testing as a Business Service

For electricians, PAT testing is a straightforward additional revenue stream. A single domestic or small commercial PAT visit typically takes 2–4 hours and can be charged depending on the number of items. Large commercial premises with hundreds of items offer significant contract potential.

Keys to a successful PAT testing service:

• Invest in a good PAT tester with automatic record generation — it cuts admin time dramatically
• Use professional-looking pass/fail labels and produce a formal certificate/report for each visit
• Set up reminder systems so clients know when their next test is due — repeat business is far easier to retain than to find
• Be clear about what you're testing: appliances only, not fixed wiring (that's an EICR)
• Price per item or per hour, depending on the volume involved

Electrical Accessories from APM

At APM Electrics Plumbing, we stock a wide range of electrical accessories for professional electricians — from extension leads and cable management to junction boxes and wiring accessories. Whether you need sundries for a PAT remedial job or consumables for your electrical toolkit, our trade counter and online store carry what you need.

Browse our electrical accessories collection or visit our trade counter for same-day availability on common items.

Summary

PAT testing is a practical, risk-based process for ensuring portable electrical appliances remain safe to use. The key points:

• PAT testing itself isn't a legal requirement — but maintaining electrical equipment safely is
• Testing frequency should be based on risk: high-risk environments need more frequent testing
• Visual inspection catches most faults and should never be skipped
• Class I items need earth continuity and insulation tests; Class II need insulation only
• Records aren't legally required but are strongly recommended for audit trail purposes
• For electricians, it's a low-cost service to add with good repeat business potential

If you're unsure whether your testing programme is appropriate, the IET Code of Practice for In-Service Inspection and Testing is the definitive reference, available directly from the IET.

Products Available from APM Plumbing & Electrical

Key test leads and protective devices for electrical testing available for trade collection or delivery:

Get It from APM Electricals

APM Electricals, 24 Western Avenue, Acton, London W3 7TZ. Call 020 8702 8080 or visit www.apmi.uk for same-day trade counter collection and next-day delivery across London and the UK.