Photograph of me PAT Testing a free-standing heater.

How often should PAT Testing be done?

There are no strict rules or legal requirements concerning the frequency of combined formal visual inspection and testing ('PAT Testing') of electrical equipment in either the workplace or, in the case of landlord or company-supplied electrical equipment, in rented accommodation or residential care homes (see 'Do we have to have Testing done?'). However, it is generally recommended Health and Safety Best Practice to usually have this work carried out on an annual basis, and this is the frequency that I normally offer any client that wishes to use my PAT Testing services. In the event of an unfortunate accident involving electricity, the governing body, the Health and Safety Executive, will probably view your organisation in a more favourable light if you can demonstrate that you have taken the matter of electrical safety seriously by, for example, providing evidence of having had periodic (usually annual) PAT Testing carried out.

If the reader really does wish to know more about the formalities of periodical PAT Testing, then s/he may be interested in reading through the rest of this page. However, the answer to the question: "How often should testing be done?" would be "Usually once a year".

Frequency of visual inspection and testing in detail

In a workplace situation in particular, if an organisation was to consider implementing a stricter regime of formal visual inspection and testing (a 'belts and braces' approach), then all of what follows below would need to be taken into account. Please note that although some of what follows is indeed relevant to landlord or company-supplied electrical equipment in rented accommodation or care homes, it is primarily concerned with the inspection and testing of electrical equipment in the workplace. Furthermore, what follows is just a very brief discussion; for detailed information, you may wish to consult a copy of the IEE Code of Practice for In-service Inspection and Testing of Electrical Equipment (ISBN: 0-85296-776-4, price £35), which includes details of the recommended frequency of inspection and testing of electrical equipment in the workplace.

First of all, we need to consider the three different types of inspection and testing that will need to be applied to workplace electrical equipment. These are:

Secondly, we also need to identify the two different classes of electrical equipment that generally need to be inspected and tested. These are:

User Checks

Section 7 of The Health and Safety at Work etc. Act 1974 puts a duty of care on employees to ensure the safety of all persons using the workplace (yes, that's right; I am referring to employees here, and not their employers). Everyone in the workplace should have simple, basic training in how to check over the electrical equipment that they use, and it is important that employees perform routine, simple safety checks. This includes checking the exterior of the plug, cable, socket outlet, etc, and making sure that cables are not trapped or trailing in a dangerous manner. Simple checks such as these need only take a moment or two, and records of such checks only need to be kept where a fault is found. Obviously, any faulty, unsafe equipment needs to be disconnected and reported to the appointed 'Responsible Person' immediately (this is typically the member of staff that is responsible for Health and Safety, but could in fact be any suitably-appointed person). Generally, user checks should be carried out with a frequency of between "before each use" (for example, with some types of equipment used in commercial kitchens) to "weekly" (for example, with some types of equipment used in schools). See the IEE Code of Practice for more details.

Formal visual inspection

These checks must only be carried out by a competent person, and typically this would be a member of staff who has had appropriate training and who has the time to make periodic checks of all of the electrical equipment in use. Formal visual inspection involves a lot more work than simple user checks of course, and includes procedures such as dismantling plugs to check connections, fuses, etc., looking for signs of overheating, checking cable runs to make sure that they don't have heavy equipment placed on top of them, making sure that items such as filing cabinets are not blocking access to the socket, plug and switch, etc. (it is Health and Safety Best Practice that plugs and switches are easily accessible, especially in the case of an emergency). Records of all formal visual inspections must be kept, even if no faults are found. Generally, it is suggested that 'in-house', formal visual inspection checks should be carried out with a frequency of between "weekly" (for example, with some types of equipment used by the public) to "twenty-four months" (for example, with some types of equipment used in hotels). See the IEE Code of Practice for more details.

Combined formal visual inspection and testing ('PAT Testing')

These checks must only be carried out by a competent person. In addition to formal visual inspection, discussed above, specialised electrical test instruments are used (usually a dedicated Portable Appliance Tester) to test for things such as earth boding, insulation strength, touch current, leakage current, substitute leakage current and functional (running) tests. It is important that the person performing the tests understands the test results and that formal recordings are taken for each test, even where no faults are found. Although it is possible that, with appropriate training, such as City and Guilds 2377, and access to suitable test instruments*, a 'competent' member of staff could legally and practically carry out combined formal visual inspection and testing (PAT Testing), it is normal practice to use the services of an outside contractor, for the same reasons perhaps that an organisation wouldn't normally ask it's staff to lay carpet, fit new new windows and do roof repairs! I am able to provide you with such a service, of course. Generally, it is suggested that combined formal visual inspection and testing ('PAT Testing') should be carried out with a frequency of between "three-monthly" (for example, with most types of equipment used on construction sites) to "forty-eight months" (for example, with some types of equipment used in shops). In practice, and in particular with ease of management in mind, a compromise is made between very frequent and very infrequent checks, and therefore PAT Testing is typically carried out on an annual basis. This is the frequency that I normally offer any client that wishes to use my PAT Testing services. See the IEE Code of Practice for more details.

The important thing to remember is that, by law, the electrical equipment, whether in the workplace or supplied by a landlord or the owner of a residential care home, has to be, in simple terms, 'safe, well-maintained and suitable for the purpose for which it is being used', and at all times. Again: whilst formal visual inspection and testing (PAT Testing) will help to determine whether the equipment meets this criteria (at the time of testing), these procedures will not, in themselves, keep you compliant with the law; the law requires that the equipment, at all times, must be 'safe, well-maintained and suitable for the purpose for which it is being used' (see 'Do we have to have Testing done?'). For example, if an item is inspected and tested and is shown to be safe but, however, becomes electrically unsafe a few months later, then it is illegal to have this item in commission, even if its condition is not known (ignorance is no excuse in the eyes of the law).

Finally, it is important to point out that the frequency of inspection and testing needs to be kept under review, especially when factors such as the environment or frequency of use, etc., change.


*Training courses and examination fees for the City and Guilds 2377-100 and 2377-200 typically cost about £400 to £500. A good quality Portable Appliance Testing device, including associated computer software, bar-code scanner and leads, etc., would set you back between £1,500 to £2,000. Some organisations consider buying their own test equipment and training up a member of staff to do what is usually an annual inspection and test. However, when you consider that instead it may only cost perhaps £60 (my minimum charge) to a couple of hundred pounds a year to have this work carried out by a competent, fully-insured and independent outside contractor (such as myself!), just think how long it would take to get a return on what could have been a £2,000 outlay, not to mention the time it would take that member of staff to do the work. Also, is it really likely that that member of staff is going to remember what to do when it's been perhaps twelve months since s/he's last done the inspection and testing? Also, would she really be happy doing the work? Furthermore, would the Health and Safety Executive really be convinced that the inspection and testing was done properly when it had been undertaken by an 'insider' with, and no disrespect, experience amounting to perhaps just per few hours a year?


“As may be necessary to prevent danger, all systems shall be maintained so as to prevent, so far as is reasonably practicable, such danger.” The Electricity at Work Regulations 1989

“It shall be the duty of every employer to ensure, so far as is reasonably practicable, the health, safety and welfare at work of all his employees.” The Health and Safety at Work etc. Act 1974

I am City and Guilds qualified in PAT Testing, and fully insured.


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