How Long Does a PAT Test Last? Certificate Validity and Retest Intervals

A PAT test doesn't come with a fixed expiry date. There is no legal requirement to retest after 12 months — or any specific period. The IET Code of Practice for In-Service Inspection and Testing of Electrical Equipment sets suggested intervals, but these vary by equipment type, environment, and usage pattern. The answer to "how long does a PAT test last?" is: it depends.

There is no standard "validity period"

No UK regulation sets a PAT test expiry date. The Electricity at Work Regulations 1989 require that electrical equipment is maintained to prevent danger. They say nothing about how often. The Health and Safety at Work Act 1974 creates a general duty to ensure safe equipment. Again, no testing frequency is specified.

The HSE confirms this on their PAT testing FAQ page: there is no legal requirement for PAT testing at fixed intervals.

What the IET Code of Practice provides are suggested initial intervals — starting points that you're expected to review and adjust based on your own experience and failure data. These intervals range from 3 months for 230V equipment on construction sites to 48 months for stationary equipment in offices. A single "12-month validity" doesn't exist in the guidance.

The widespread assumption that PAT testing is an annual obligation comes from testing contractors who schedule annual visits and from organisations that default to 12 months because it's simple. Simple doesn't mean correct. For most office equipment, annual testing is more frequent than the IET Code of Practice recommends. For high-risk environments, it may not be frequent enough.

For a full breakdown of the legal position, see our guide on whether PAT testing is legally required.

Retest intervals by equipment and environment

The IET Code of Practice recommends different intervals depending on three factors: the type of equipment, the environment it's used in, and the level of inspection.

Here's a summary of combined inspection and testing intervals — the full electrical test that most people mean when they say "PAT testing."

Environment	Stationary equipment	Portable equipment	Handheld equipment	Extension leads
Office / shop	48 months	48 months	24 months	48 months
Industrial / high-use	24 months	12 months	12 months	12 months
Construction (230V)	3 months	3 months	3 months	3 months
Construction (110V)	6 months	6 months	6 months	6 months

These are initial intervals. Formal visual inspections are recommended at shorter intervals — typically half the combined inspection and test interval.

This table is a summary. The full IET Code of Practice tables include more equipment categories and distinguish between user checks, formal visual inspections, and combined inspection and testing. See our PAT testing frequency guide for the complete breakdown, or use the PAT testing frequency calculator to get a recommended schedule for your specific equipment and environment.

The point is clear: a PAT test on a desktop PC in an office has a much longer useful life than a PAT test on a handheld power tool on a building site. Treating them the same wastes money on one and risks safety on the other.

What a PAT test "certificate" actually is

Strictly speaking, PAT testing doesn't produce a certificate. It produces a record or report.

The term "PAT test certificate" is used informally — by contractors, landlords, and property managers — but it has no formal legal status. Unlike an Electrical Installation Condition Report (EICR), which is a standardised document issued by a qualified electrician under BS 7671, a PAT test record has no prescribed format and no regulatory body overseeing its issue.

What a PAT test record should contain:

A description of the appliance and its unique identification number
The location of the appliance
The date of the test
The name (or identification) of the person carrying out the test
The tests performed and the results (actual values, not just pass/fail)
The overall pass or fail outcome
The date of the next scheduled test

That last item — the next test due date — is the closest thing a PAT test has to an expiry date. It's the tester's recommendation for when the appliance should next be inspected and tested, based on the IET Code of Practice guidance and their professional judgement.

If a contractor hands you a document titled "PAT Test Certificate," it's a record of work done. It's useful evidence for compliance. But it's not a certificate in the way a gas safety certificate or an EICR is. No regulatory body issued it, and no regulation defines its format.

For more on what your records should contain and how to maintain them, see our guide on PAT testing records.

When to retest earlier than scheduled

A PAT test result is a snapshot. It tells you the appliance was safe on the date it was tested. Conditions change. Several situations should trigger retesting before the next scheduled date, regardless of how recently the appliance was tested.

Visible damage. If a cable is frayed, a plug is cracked, or the casing is damaged, the appliance should be taken out of service and retested (or repaired and then retested) immediately. A PAT test from last month doesn't make a visibly damaged appliance safe today.

After a repair. Any appliance that has been repaired — a new plug fitted, a cable replaced, an internal fault fixed — needs retesting before it goes back into service. The repair may have introduced new faults.

After a reported incident. If someone reports an electric shock, a tingling sensation, a burning smell, or any other electrical near-miss involving a specific appliance, that appliance should be isolated and retested. Don't wait for the next scheduled test.

Change of environment. Equipment moved from a clean office to a dusty workshop is now in a higher-risk environment. The original test interval was based on the original environment. Reassess and retest.

Change of use pattern. A printer that sat on a desk for two years and is now moved between floors on a trolley every day is subject to much more cable stress. The stationary testing interval no longer applies.

After a period out of service. Equipment stored in a damp storeroom for six months may have degraded. A visual inspection and retest before returning it to use is prudent.

The IET Code of Practice makes clear that the suggested intervals assume equipment is used in a consistent environment and doesn't suffer damage between tests. When those assumptions no longer hold, the interval resets.

When to extend intervals

The IET Code of Practice doesn't just allow you to shorten intervals. It explicitly encourages you to extend them where the evidence supports it.

The Code of Practice states: where experience of the type and condition of equipment used in particular premises shows the equipment to be consistently in a satisfactory condition, the intervals between inspections and tests may be lengthened.

This is called review-based risk assessment, and it's how a mature PAT testing programme should work. Conditions that support extending intervals:

Consistently clean results. If a category of equipment has passed every test over two or more test cycles with comfortable margins, the current interval may be too short. You're spending time and money testing equipment that shows no signs of deterioration.

Low-risk environment. An air-conditioned, carpeted office with no dust, moisture, or temperature extremes puts minimal stress on equipment. Degradation is slower. Longer intervals are justified.

New equipment with no wear. A laptop purchased six months ago with a moulded plug and an intact cable doesn't need the same testing frequency as a ten-year-old kettle with a rewirable plug.

Low failure rates. The IET Code of Practice suggests that a failure rate approaching 0% indicates the testing interval may be too short. If you're testing annually and nothing ever fails, consider moving to 24 months and monitoring the results.

To extend intervals defensibly, you need records. An auditor won't accept "we decided to test less often because nothing seemed broken." They will accept "our failure rate for this equipment category has been below 2% over three test cycles at 12-month intervals, so we've extended to 24 months per the IET Code of Practice review guidance." That's a risk-based decision backed by data.

Labels and the "next test due" date

Most PAT-tested equipment carries a label showing the test date, the tester, and the next test due date. These labels are useful. They let anyone quickly see whether an appliance is within its testing window. But the date on the label is a reminder, not a legal deadline.

If the "next test due" date passes, the appliance isn't automatically failed or condemned. It hasn't become unsafe overnight. What it means is that the tester's recommended interval has elapsed and the appliance should be retested as soon as practical.

An appliance with an overdue test date is in the same position as an appliance that has never been tested: you can't demonstrate that it's currently maintained. The longer it remains overdue, the weaker your compliance position. But the solution is to retest it — not to discard it.

Some organisations are overly rigid about label dates, removing appliances from service the day after the label expires. This is unnecessary unless there's also visible damage or another reason for concern. The pragmatic approach is to retest promptly, within days or weeks, not to treat the label as a hard cut-off.

For more on labelling requirements and best practice, see our PAT testing labels guide.

Managing retest schedules

Knowing the right intervals is only useful if you track them. A PAT test result without a system for triggering the retest is a one-off exercise, not a maintenance programme.

Maintain a register. Every appliance should be on a central register (sometimes called an asset register or PAT register) with its unique ID, description, location, last test date, and next test due date. This is the backbone of your PAT testing programme. See our guide on PAT register templates vs software for options.

Set reminders. Whether you use a spreadsheet, a calendar, or dedicated software, you need a system that alerts you when retests are due. Relying on memory or periodic label checks is how appliances fall through the gaps.

Group appliances for batch retesting. Testing one appliance at a time as each comes due is inefficient, especially if you outsource to a contractor. Group appliances by location or retest date and schedule batch testing sessions. Many organisations align this with quarterly or annual health and safety reviews.

Schedule around operational needs. If your business has quiet periods — school holidays, factory shutdowns, seasonal lulls — that's the time to schedule batch testing. Equipment is available, disruption is minimal, and you start the busy period with everything freshly tested.

Review intervals after each cycle. After each round of testing, review the results. Adjust intervals up or down based on failure rates. Record the rationale for any changes. This is the ongoing risk assessment the IET Code of Practice expects.

For a step-by-step approach to building a retest schedule, see our guide on PAT testing schedules for the workplace.

Summary

A PAT test has no fixed expiry. The "validity" of a test result depends on the equipment type, the environment, and whether conditions have changed since the test was performed. The IET Code of Practice gives you starting intervals. Your own failure data and risk assessment refine them.

The key principles:

There is no legal requirement to retest at any specific interval
The IET Code of Practice provides suggested initial intervals ranging from 3 to 48 months
Retest earlier if equipment is damaged, repaired, moved, or involved in an incident
Extend intervals if failure rates are consistently low and conditions haven't changed
The date on a PAT label is a reminder, not a legal deadline
Records and a managed retest schedule are what make the system work

Use our PAT testing frequency calculator to get recommended intervals for your equipment, and our PAT compliance checker to identify any gaps in your current approach.

PATvault tracks retest dates for every appliance in your register and sends reminders before they're due. No missed retests, no guesswork about what's overdue.

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