The Electricity at Work Regulations (1989) requires “All electrical systems shall be maintained so as to prevent, so far as is reasonably practicable, any danger”. This is interpreted as covering the fixed electrical installation as well as portable and transportable equipment connected to it. The Regulations also state “It is the duty of every employer and self employed person to comply with the provision of these Regulations.”
Unsafe electrical appliances can cause fires and personal injury. In fact in 2007 19%of house fires were caused by electrical faults and a further 25% were caused by people not using electrical equipment and appliances properly.
A PAT test or Portable Appliance Test is a test to ensure that any electrical portable appliance is safe. In reality this means electrical devices with a plug on the end. So not only laptops, computers and kettles but microwave ovens and even washing machines. 
As you can see from the items that need to be tested, it is a good idea for both employers and landlords to have this equipment tested. The most common PAT testing interval is once every 12 months. Recommended intervals do vary, and will depend on design, location and use of each piece of equipment.
It is a little known fact that it is not stated anywhere in the health and safety regulations that an individual has to have any qualifications to PAT Test. It does state however, that it must be done by a competent person who has been given instruction. So, if you have a lot of appliances to test – you work for a company or have multiple rented properties, it might be a cost effective idea to get on a PAT testing training course.
You will also need to purchase some PAT testing equipment. This has come down in price considerably over the last a few years and is now relatively cheap.
Once the device has been tested you will need to display evidence of testing. Make this visible by affixing stickers to the appliance with the date and a message stating  ”Tested For Electrical Safety’ and ‘PASSED’ on them. Obviously remove or repair any items that fail the PAT test.
If you decide to hire a professional electrician or electrical company to perform your PAT testing, the costs will depend on the time taken to test all appliances thoroughly.The time taken will depend on how easy it is to get to the appliances for testing, any furniture that needs to be moved for example and of course the number of appliances.
There are around 30 deaths and 4,000 accidents annually in the UK involving electrics. It is important to ensure that any electrical appliances and fittings within the property you rent out are safe.However, unlike Gas Safe regulations, there is no legislation that demands you must have a electrical safety certificate. However, should any electrical fittings or appliances within your rental property cause actual harm to the tenant, you could be held liable.