PAT testing – how often?

PAT testing is widely accepted as the most effective, preventative maintenance measure to comply with legal obligations and ensure electrical equipment is fit for purpose and safe to use.

One of the more common areas of concern is how often PAT testing should be carried out to maintain compliance and safety standards, without creating overly-onerous maintenance and testing demands on employers and landlords.

PAT testing – how often should it be carried out?

The requirements are that testing should be performed ‘regularly’, but there are no set rules or guidelines determining what qualifies as regular, or specifying how often PAT testing should be carried out.

This is due to the practicalities of different environments and different types of equipment – each requiring different approaches.

A general rule of thumb is that PAT testing should, at a minimum, be carried out every 2 years. But this is a general indication, and certain factors should be considered to determine the frequency of testing for your circumstances. These include:

  • Location of the equipment
  • Equipment type
  • Frequency of use
  • Competence of users
  • The installation method
  • Testing and maintenance records
  • Whether the equipment is on hire

This means taking a flexible, risk-based approach to determine the most suitable approach and frequency for testing of your portable electrical equipment.

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Through risk assessments, duty holders can take a systematic, measured and transparent approach that considers factors such as the environment where the equipment is used, the type of equipment in question and how it is used, to ensure continued compliance with H&S regulations.

What to consider to determine frequency of PAT testing?

It will be for the duty holder – the employer, landlord or self-employed individual for example – to decide on the frequency of testing that would ensure safety of portable appliances.

A number of factors should be considered to establish an ideal frequency and resulting testing schedule:

  1. Equipment Type (portable, handheld or transportable)
  2. Equipment Class (Class I or Class II)
  3. Equipment use (continuous, infrequent, rough)
  4. How long equipment has been in service (Age)
  5. If equipment is moved around & how frequently
  6. Competence of personnel using the equipment
  7. Where equipment is used (outdoors, construction sites, hazardous atmospheres etc)
  8. Previous test results
  9. Manufacturers guidelines & recommendations
  10. Equipment modifications or repairs

What is the difference between Class 1 and Class 2 appliances?

Class 1 and Class 2 appliances require PAT testing but are tested differently.

Both types of appliance are powered by mains voltages and are required to provide at least two levels of protection to the end user. PAT testing checks that both levels of protection are working effectively.

  • Class 1 Appliances Users are protected by a combination of basic insulation and the provision of an earth connection e.g. fridges, microwaves, toasters.
  • Class 2 Appliances Users are protected by at least two layers of insulation, ‘double insulated’ e.g. computers, plastic power tools.

A major consideration is the type of equipment, which could include:

  • Stationary appliances have a mass exceeding 18kg in weight and do not provide a carrying handle.
  • Information Technology equipment includes computers, mains powered telecommunications equipment and other equipment used in general business use.
  • Movable equipment is 18kg or less and is not fixed.
  • Portable appliances are less than 18kg and intended to be used whilst in operation or an item that can be easily moved from 1 place to another.
  • Handheld appliances are held in the hand during normal use.
  • Fixed equipment is fastened to a support or otherwise secured in a specific location. It also includes equipment connected to the fixed installation via a Fused Connection Unit (FCU).

For example, handheld appliances may be at greater risk of damage and wear than stationary equipment.

You would also look at how often equipment is used. The greater the usage of an appliance, the more frequent the testing requirement should be to account for increased risk of equipment damage, deterioration and faults.

Are there any guidelines for PAT testing frequency?

Although there are no requirements for PAT testing frequency, there are recommendations:

Offices, Shops and Hotels

Class 1 equipment including stationary and IT equipment should be tested every 48 months.

Moveable equipment such as extension leads and portable equipment should be tested every 24 months.

Handheld equipment should be tested every 12 months.


All Class 1 equipment in schools should be PAT tested every 12 months.

Class 2 equipment should be tested every 48 months.


All 110V equipment used on construction sites should be tested every 3 months.


All industrial sites, including commercial kitchens should have portable and handheld equipment tested every 6 months. Stationary, IT and moveable equipment should be tested every 12 months.

Public Use Equipment

Stationary and IT equipment such as computers should be tested every 12 months.

Moveable, portable and handheld equipment falling into Class 2 should be tested every 12 months.

Moveable, portable and handheld equipment falling into Class 1 should be tested every 6 months.

How often should visual examinations be carried out?

Regular visual inspections by the user combined with formal visual inspections by a ‘competent’ person together are effective in reducing the electrical appliance hazards and failure.

As such, safety programmes should also include visual examinations, to support equipment testing. The frequency of visual examinations, as well as electrical tests, should also be regularly reviewed.

User inspections can be carried out by any member of staff. These should be visually-led, non-technical and non-intrusive. Operators would not be expected to open up casing or use testing tools.

It would not be necessary to record these checks, but in the event an issue is identified, there should be a clear process in place for employees or operatives to notify a relevant individual in the organisation of the fault to be rectified.

Training is helpful for operatives to understand what to look for as part of their general equipment use and to familiarise with the process to notify of faults.

Do you have a question about PAT testing?

Given the purpose of testing is to maintain a safe environment for workers, customers and those who hire equipment, PAT testing should be carried out as often a necessary to ensure equipment is functioning properly, without becoming overly onerous on the responsible person.

For help and advice on your PAT testing and electrical compliance, contact Emelec’s team of experienced electrical engineers.


This article is for informational purposes only and does not constitute direct advice.