One of the most common questions about portable appliance testing is "how often do I need to do it?". The short answer: there is no single legally fixed interval. The correct frequency depends on the risk each appliance is exposed to, and that risk is assessed per environment and per equipment type.
This guide explains the risk-based approach recommended by the IET Code of Practice, gives typical intervals for common environments, and shows how NETS PAT keeps track of what's due next.
Why intervals are risk-based
The Electricity at Work Regulations 1989 require equipment to be "maintained to prevent danger" but deliberately do not specify a testing frequency. That decision is left to the duty holder, guided by risk. The main factors that increase risk are:
- Environment — wet, dusty, hot, vibrating, or outdoor conditions cause equipment to deteriorate faster than clean, dry indoor environments
- Frequency of use — equipment used constantly wears out faster than occasional-use items
- User — equipment handled by the public, or by people unfamiliar with it, is at greater risk of damage
- Equipment type — handheld and portable appliances are moved and knocked; fixed-wiring-connected and IT equipment is rarely disturbed
- Equipment construction — Class I equipment with an earth connection generally needs more frequent testing than double-insulated Class II
- Previous test history — if an appliance has failed or been damaged before, it should be checked more often
Because these factors vary, a sensible interval can range from 3 months for high-risk hire or construction equipment up to 4 years for low-risk office IT.
Typical intervals by environment
The table below summarises the common guidance used across the industry. Treat it as a starting point — your own risk assessment should confirm or adjust it.
| Environment / equipment | Typical interval | Notes |
|---|---|---|
| Construction sites, building & repair | 3 months | Hand tools and site equipment exposed to harsh conditions and high-frequency use |
| Hire equipment (high risk) | 3 months | Equipment leaving the premises must be safe every time; many hire businesses test before each hire |
| Hire equipment (general) | 6 months | Standard hire stock such as power tools and appliances |
| Industrial / manufacturing | 6 months | Factory floors, workshops, and similar environments |
| Schools, hotels, leisure centres | 12 months | Equipment used by the public and by many different people |
| Offices, shops, general commercial | 24 months | Standard equipment in low-risk indoor environments |
| Office IT equipment (desk-based) | 4 years | Computer equipment in low-risk, stationary environments — 48 months per IET guidance |
| Seasonal equipment | Before each use | Equipment such as fans, heaters, or fairground gear should be tested before each season |
| Fixed equipment (fridges, washing machines) | 12 months | Stationary but higher-wear appliances; interval varies with environment |
Retest interval calculator
Not sure what interval to set? Pick the environment and get a typical starting point.
Guidance only, based on the IET Code of Practice for In-Service Inspection and Testing of Electrical Equipment. Confirm the interval with your own documented risk assessment. NETS PAT lets you set any interval from 3 months to 4 years per asset.
A note on "annual" testing
"Yearly PAT testing" is a common habit, but it is not always right. Some equipment needs testing far more often; some office IT genuinely doesn't need an annual test. The correct approach is documented risk assessment — annual testing is simply what many assessments conclude for standard environments.
Why the interval needs a record
An interval is only useful if something tracks it. When a certificate expires and nothing flags it, appliances quietly fall out of compliance. That's the gap between "doing PAT testing" and "managing PAT testing".
NETS PAT stores a risk-based retest interval against every asset — set from a range of 3 months to 4 years — and shows you exactly what's due, overdue, or expiring soon across every client and location. Nothing slips through because a spreadsheet was never updated.
New equipment
Brand-new equipment straight from a reputable supplier is covered by its own product testing, so it doesn't need a PAT test on day one. However, best practice is to:
- Add it to the asset register immediately
- Do a visual inspection when it arrives (transport damage is common)
- Record its start-of-life retest interval so the clock starts running
In NETS PAT you can add new assets during a rapid scan session — scanning an unknown barcode creates the asset on the spot with a fresh test history.
Frequently asked questions
Is yearly PAT testing a legal requirement?
No. The regulations require equipment to be maintained to prevent danger; the frequency is determined by risk assessment. Annual testing is common but not mandatory, and can be more or less frequent depending on the environment.
How often should hire equipment be PAT tested?
Hire equipment is a special case because it leaves your control and is used in unknown conditions. The IET guidance recommends testing before each hire where risk is high, with 3–6 months typical for standard hire stock.
Do new appliances need testing?
Not immediately — they're covered by the manufacturer's safety testing. Add them to your register and set their retest interval so they're tested from the correct point onwards.
Can NETS PAT remind me when testing is due?
Yes. Every asset carries its own risk-based interval, and the dashboard flags due, overdue, and upcoming tests. You can review intervals per asset or in bulk for each client.
Who decides the interval?
You do — informed by the IET Code of Practice guidance and your own risk assessment. NETS PAT gives you the full 3-month to 4-year range to record whatever your assessment concludes.
Get your intervals under control
Track every asset, its interval, and what's due next — automatically. Start free or explore the full feature list.