Security Insights
What Is PAT Testing? Everything You Need to Know (UK Guide)
What PAT testing is, what it involves and what UK law and HSE actually require: appliance classes, how often to test and who can do it.
Table of contents
Imagine your office, shop or workshop as a stage, and the kettles, computers, printers, chargers and heaters as the performers. Each one has to do its job every day without sparks, shocks or worse. So, what is PAT testing? In short, it is how you check that those everyday appliances are still safe to use.
A quick note before you read on: British Engineers doesn’t carry out PAT testing. We install and upgrade commercial electrical systems, alarms and security systems across Greater Manchester, and we’ve written this guide so you know what PAT testing involves, what the law actually asks of you and what to ask a tester for.
What is PAT testing?
PAT stands for portable appliance testing. It is the examination of electrical appliances and equipment to make sure they are safe to use. Most faults can be spotted by a careful visual inspection, and some can only be found with an electrical test, so a proper PAT test combines both. The industry guide now calls it in-service inspection and testing of electrical equipment, but almost everyone in the UK still says PAT testing.
According to the Health and Safety Executive (HSE), it is one part of a bigger picture: keeping electrical equipment safe in workplaces and properties. Done well, it is a way of managing risk before something goes wrong, rather than a box to tick once a year.
The PAT testing process: from visual inspection to electrical testing
HSE describes three levels of check. Each one adds to the one before it:
User check
Whoever uses the item, before using it
A quick look at the plug, cable and casing for damage, scorching or loose parts.
Formal visual inspection
A trained member of staff or a tester
A closer, recorded look, including opening the plug where it can be opened to check the fuse and wiring.
Inspection and testing
A competent person with a PAT tester
The visual inspection plus electrical tests such as earth continuity and insulation resistance.
1. User checks. Whoever uses the appliance takes a quick look before plugging it in: frayed or damaged cables, cracked plugs, scorch marks, loose parts or tape holding things together. A kettle with a split cable or a computer lead with a bent plug should go straight out of use.
2. Formal visual inspection. A trained person looks more closely and records what they find, including opening the plug, where it can be opened, to check the fuse rating and that the wires are held firmly. HSE says most electrical safety defects can be found this way.
3. Combined inspection and testing. Some faults can’t be seen, so a competent person uses a PAT tester to check them. The usual PAT tests are:
- Earth continuity, which checks that the earth connection on a Class I appliance is intact.
- Insulation resistance, which checks that there is no dangerous path for current through the insulation.
- Polarity, for extension leads and detachable power leads, to check the wires are connected the right way round.
- A functional check, to confirm the appliance works as it should once tested.
Where an insulation test isn’t suitable, for example on some IT equipment, the tester may use a leakage test instead. The results tell you whether the item can stay in use, needs repair or should be taken out of service.
Is PAT testing a legal requirement in the UK?
No, not in itself. The Electricity at Work Regulations 1989 require that electrical equipment which could cause injury is maintained in a safe condition. HSE is clear that the regulations don’t say what has to be done, by whom or how often, so they don’t make PAT testing, or testing every year, a legal requirement.
So the PAT testing requirements in the UK come down to one duty: keep equipment safe. Compliance is about the result, not a date on the calendar. What the law does expect is that you can show your equipment is kept safe. PAT testing is the most common practical way to do that, which is why insurers, landlords and clients often ask for it. Some other points that come up a lot:
- Labels and records are not required by law, but HSE says they are a useful way to manage and show your maintenance.
- New equipment should arrive safe and doesn’t need a formal PAT test, just a visual check that it hasn’t been damaged.
- Hired tools should be inspected and tested by the hire company before each hire.
- Standards and guidelines: the main references are HSE’s guidance and the IET Code of Practice for In-service Inspection and Testing of Electrical Equipment (5th edition, 2020). Neither is law, but both are what testers work to.
Landlords who supply appliances also have to keep them safe. PAT testing UK rules for rented homes differ for houses in multiple occupation and in Scotland, so check the guidance that applies to your property.
Why is PAT testing important?
Because faulty appliances cause electric shocks and fires, and most faults start small: a crushed lead, a cracked plug, a loose wire. Regular checks catch them before anyone gets hurt. Does it matter for the business? Yes. Finding a damaged extension lead early saves money compared with a fire, lost working days or an awkward conversation with your insurer, and a simple record shows you have taken your duty seriously.
Know your appliance classes: Class 1, 2 and 3 explained
Electrical appliances fall into three classes, and the class decides which tests are needed. You’ll often see them written as Class I, II and III.
| Class | How it protects you | Examples | What is usually checked |
|---|---|---|---|
| Class 1 | An earth wire, usually with a metal case | Kettles, toasters, microwaves, washing machines, many heaters | Visual inspection, earth continuity and insulation tests |
| Class 2 | Double insulation, no earth (shown by a square inside a square) | Hairdryers, many power tools, TVs, most chargers | Visual inspection and an insulation test |
| Class 3 | Runs on safety extra-low voltage | Laptops, phones and LED lamps run from a separate low-voltage supply | A visual check; the charger or power supply (often Class 2) is the part tested |
Class 1 appliances generally need more attention because their safety depends on an earth connection that has to stay intact. Knowing the class of each item lets a tester do the right checks without wasting time on tests that don’t apply.
How often should you get PAT tested? Exploring PAT test frequency
There is no single answer, and no fixed yearly rule. HSE says the frequency of inspection and testing depends on the type of equipment and the environment it is used in. A power tool on a construction site should be examined far more often than a lamp in a hotel bedroom.
Things that push the interval shorter:
- A harsh environment, such as building sites, workshops, kitchens or anywhere wet, dusty or outdoors. Site tools usually run on 110V for this reason and are checked more often.
- Heavy use or frequent moving, like vacuum cleaners, extension leads and kettles.
- Faults found last time. If an item failed or needed repair, check it more often.
HSE gives a useful example: a high street travel agent decided its computers, printers and fax, which rarely moved, needed a visual inspection every five years, while its heavily used vacuum cleaner needed one every six months. HSE’s leaflet INDG236 includes a table of suggested starting intervals for offices, shops and other low-risk places, and HSG107 covers higher-risk work. Base your schedule on a simple risk assessment and adjust it as you learn which items get damaged.
What needs PAT testing?
Anything that plugs into the mains and could cause injury if it became faulty. In practice that means:
- Portable and moveable equipment: kettles, heaters, fans, vacuum cleaners, microwaves, power tools.
- IT and office equipment: computers, monitors, printers, and in some cases servers in racks.
- Leads: extension leads, multi-way adaptors and detachable power cables, which often fail first.
- Fixed and built-in appliances such as hand dryers and some white goods, which are inspected in place.
PAT testing covers the appliances, not the building. The wiring, sockets and distribution boards are checked separately by an inspection of the fixed installation, carried out by an electrician.
Who should carry out PAT testing? The role of qualified PAT testers
The person has to be competent for the work, and HSE says it doesn’t have to be an electrician. In many low-risk workplaces a sensible member of staff with enough knowledge and training can do the visual inspections. Combined inspection and testing needs more: the right test equipment, the ability to use it properly and the ability to understand the results.
There is no single legal qualification for a PAT tester, but many people choose a tester who has completed a recognised course on the IET Code of Practice. Responsibility stays with the duty holder, usually the employer or whoever runs the premises, whoever does the testing.
If you use PAT testing services, ask for a record of each item: what it is, its class, which tests were done and the result. For busy workplaces, schools, hotels and offices with hundreds of items, a specialist tester will usually be quicker and keep better records. For a small office, trained staff doing regular visual checks, with testing where it is needed, can be enough.
PAT testing and the rest of your electrics
Safe appliances are only half the picture. If you are refitting a unit, adding circuits or upgrading the wiring in a shop, office or warehouse, that work is designed, installed and tested by electricians. If you’re planning work like that, see our commercial electrical installation in Manchester page.
Frequently asked questions
What does PAT stand for?
PAT stands for portable appliance testing: the inspection and testing of electrical appliances to check they are safe to use. In the IET Code of Practice it is called in-service inspection and testing of electrical equipment.
Is PAT testing a legal requirement?
No. The Electricity at Work Regulations 1989 require electrical equipment at work to be maintained in a safe condition, but they don’t say how or how often. PAT testing is the usual practical way to show you are meeting that duty.
How often should PAT testing be done?
It depends on the equipment and where it is used. HSE does not set a yearly rule: tools on a building site need checking far more often than office equipment. Use a risk assessment, and HSE’s INDG236 table as a starting point for low-risk places.
When is PAT testing required?
When your risk assessment says an item is due, after a repair, or when an insurer, landlord or client asks for it. There is no single legal date: the interval depends on the equipment and where it is used.
Do new appliances need PAT testing?
No. HSE says new equipment should be supplied in a safe condition and doesn’t need a formal PAT test, but it should be checked visually for damage before use.
Who can do PAT testing?
Anyone competent to do it. A trained member of staff can carry out visual inspections; combined inspection and testing needs the right tester and someone who can use it and understand the results. It does not have to be an electrician.
Does British Engineers do PAT testing?
No, we don’t offer PAT testing. We install and upgrade commercial electrical systems and security systems in Manchester and Greater Manchester.
Final thoughts
PAT testing isn’t about a sticker on every plug. It’s about knowing your kettles, chargers, heaters and tools are safe, checking the risky ones more often and fixing problems before someone gets hurt. Start with user checks, add formal inspections and testing where the risk calls for it, and keep a simple record of what you’ve done.
Sources
- HSE: Portable appliance testing (PAT) FAQs
- HSE: Maintaining portable electric equipment in low-risk environments (INDG236)
- HSE: Maintaining portable and transportable electrical equipment (HSG107)
- legislation.gov.uk: The Electricity at Work Regulations 1989, regulation 4
- IET: The 5th Edition of the Code of Practice for In-service Inspection and Testing of Electrical Equipment (2020)
