How Frequently Should PAT Testing Be Done? UK Intervals
One of the most common questions we get asked at Electrical Testing London is how frequently should PAT testing be done. It's a fair question, and the answer isn't as straightforward as most people expect. There's no single legal frequency written into UK law, which means the responsibility falls on duty holders to determine appropriate intervals based on the type of equipment, the environment it's used in, and the level of risk involved.
Getting this wrong can leave landlords, business owners, and facility managers exposed to liability, insurance disputes, and genuine safety hazards. Getting it right means your appliances are checked at sensible intervals without wasting money on unnecessary retesting. As qualified engineers carrying out PAT testing across London and the South East, we've put together this guide to break down the recommended intervals, explain what drives them, and help you set a testing schedule that actually fits your situation.
What PAT testing covers and who needs it
PAT testing, or Portable Appliance Testing, is the process of inspecting and testing electrical equipment to check it is safe to use. The process combines a visual inspection with electrical tests carried out using specialist equipment. A qualified tester checks items like the plug, cable, casing, and internal components for signs of damage, wear, or faults that could cause electric shock or fire.
What counts as a portable appliance
The term "portable" covers more than you might think. It refers to any electrical appliance that can be connected to the mains via a plug, which includes everything from handheld power tools and desk fans to fridges, kettles, and floor-standing photocopiers. If it has a plug and connects to the mains, it almost certainly falls within scope.
Just because an appliance rarely moves does not mean it is exempt - a fixed floor lamp in an office still needs to be included in your PAT testing programme.
Equipment is typically grouped into classes based on how it is protected against electrical faults. Class I appliances rely on both insulation and an earth connection for safety, while Class II appliances use double or reinforced insulation and need no earth. This distinction matters because it affects both the tests applied and how frequently should PAT testing be done for each item, since Class I equipment often carries a higher risk profile.
Who has a duty to carry out PAT testing
If you are an employer, landlord, or business owner responsible for electrical equipment used by others, the duty to keep that equipment safe falls on you. The Electricity at Work Regulations 1989 and the Health and Safety at Work Act 1974 both place a clear legal obligation on duty holders to maintain electrical equipment in a safe condition throughout its working life.
Landlords renting out Houses in Multiple Occupation (HMOs) must ensure any portable appliances provided with the tenancy are safe for use. Commercial businesses need to cover all equipment used by employees and visitors on their premises. Even sole traders working from home should consider any appliances used for business purposes, as these fall under health and safety obligations rather than domestic exemptions.
What the law and HSE guidance really say
No piece of UK legislation sets a fixed PAT testing interval. This surprises many landlords and business owners who assume there is a specific legal requirement to test every twelve months. The Electricity at Work Regulations 1989 require duty holders to maintain electrical equipment in a safe condition, but the regulations do not specify how frequently should PAT testing be done in any given workplace or property.
What HSE guidance actually recommends
The Health and Safety Executive (HSE) directs employers to use a risk-based approach when deciding testing intervals. Their guidance points to the IET Code of Practice for In-Service Inspection and Testing of Electrical Equipment as the recognised standard, which sets out suggested frequencies based on equipment type and environment rather than imposing blanket rules. The document is not law, but HSE treat it as the benchmark for reasonable compliance.
If you follow the IET Code of Practice intervals and document your decisions, you are in a strong position to demonstrate due diligence should any incident occur.
What your legal obligation actually requires
Your duty is to show that you assessed the risk, chose a reasonable testing frequency, and kept records to prove it. This means two organisations in different industries could legitimately run very different testing schedules for the same type of appliance. A power drill used daily on a construction site needs far more frequent testing than an identical drill kept in a school cupboard and used once per term. The law asks for evidence of a sensible decision, not a specific date on a calendar.
How to set a PAT testing frequency by risk
Setting your own testing schedule starts with a structured risk assessment rather than picking an arbitrary interval. The key is to look at the equipment you use, the conditions it operates in, and who uses it. Once you apply those factors consistently, how frequently should PAT testing be done for each item becomes a much clearer question to answer for your specific situation.
The four factors that drive your decision
The IET Code of Practice points to four main variables when determining a testing interval: the type of equipment and its class, the environment where it is used, how frequently it is handled or moved, and who the users are. Rough handling by multiple users in a demanding environment increases risk significantly, while office equipment used by a single person at a fixed desk sits at the lower end of the risk scale.
Equipment that moves between sites or users needs more frequent inspection than items left permanently in one place.
Building a simple risk assessment record
Your risk assessment does not need to be complicated, but it does need to be written down and dated. For each category of appliance, record the environment, the user group, the frequency of use, and any history of faults or damage. From there, assign a testing interval you can justify based on the evidence you have gathered.
Reviewing your records each time a test is completed also lets you spot patterns, such as a particular appliance type failing repeatedly, which is a clear signal to shorten the interval rather than wait for the next scheduled check. This approach keeps your programme active rather than fixed to an arbitrary annual date.
Typical PAT testing intervals by environment
The IET Code of Practice sets out suggested intervals by equipment type and working environment, and these figures give you a practical starting point before you apply your own risk assessment. While your specific circumstances may shift these intervals up or down, the table below reflects the broadly accepted guidance used by engineers and safety managers across the UK.
| Environment | Equipment type | Suggested interval |
|---|---|---|
| Construction sites, outdoor use | Portable power tools, extension leads | 3 months |
| Industrial and manufacturing | Heavy-use portable equipment | 6 months |
| Commercial kitchens and hospitality | Appliances with regular handling | 6-12 months |
| Offices and retail | IT equipment, desk appliances | 2-4 years |
| Schools and public buildings | Mixed portable equipment | 12 months |
| Domestic rental properties (HMOs) | Landlord-supplied appliances | 1-2 years |
Construction, industrial, and outdoor sites
Equipment used in high-risk environments takes far more physical punishment than office appliances, and the recommended intervals reflect that. Portable power tools on a construction site typically need checking every three months, and extension leads used outdoors in wet or dusty conditions should follow the same schedule. If you are asking how frequently should PAT testing be done in an industrial workshop, the answer is normally every six months at a minimum.
Offices and low-risk commercial premises
IT equipment and desk-based appliances in a clean, low-traffic office sit at the opposite end of the risk spectrum. The IET Code suggests intervals of two to four years for this category, provided you carry out regular visual checks between tests and keep a record of any reported damage or faults.
Shortening an interval based on a pattern of faults is always safer than extending it purely to reduce cost.
PAT testing records, labels, and common mistakes
Once testing is complete, the work is not finished. Keeping accurate records is just as important as the testing itself, because records are what prove your compliance if an accident occurs, an insurer queries a claim, or a health and safety inspector requests evidence. Your documentation should confirm what was tested, who carried out the tests, the results, and the date of the next scheduled check.
Keeping records that hold up
Your test records should be stored in a format you can retrieve quickly, whether that is a digital log or a physical folder. Each entry should include the appliance description, its unique identifier, the test date, the pass or fail result, and the name of the qualified tester. If you are thinking about how frequently should PAT testing be done, your records also help you spot whether a particular item is failing repeatedly, which is a clear signal to bring that interval forward.
A record that cannot be located when needed provides the same protection as no record at all.
Labels and what they actually tell you
PAT labels show the date of the last test and the result, typically as a pass or fail sticker applied to the appliance or its cable. They are a visible prompt for users and a quick reference for managers, but they are not a substitute for a full written record. A label alone does not confirm the scope of testing, who carried it out, or what specific checks were performed.
Common mistakes to avoid
The most frequent errors we see are testing on a fixed annual cycle regardless of risk, failing to include all in-scope equipment, and not updating records after remedial work. Skipping the visual inspection and relying solely on the electronic test is another common shortcoming, since many faults are visible before they appear on a meter reading.
Final checks
Understanding how frequently should PAT testing be done comes down to three things: the type of equipment, the environment it operates in, and a documented risk assessment that justifies your chosen intervals. There is no single legal frequency, so the burden is on you to make a reasonable, evidenced decision and record it properly.
Your records, labels, and testing schedules all work together as a practical safety system rather than a box-ticking exercise. Checking the right appliances at the right intervals protects your staff, tenants, and visitors, and it gives you clear evidence of due diligence if questions arise later. Reviewing your intervals regularly, especially after any equipment failure or change in working conditions, keeps your programme accurate rather than outdated.
If you need qualified engineers to carry out PAT testing at your London or South East property, request a PAT testing quote and we will get back to you promptly.
