In general, anything that has a plug or a flexible connection to a fused spur is classed as a portable appliance which should be PAT tested, this includes extension leads and power leads.
A PAT test is a simple test with specialist equipment that ensures that an electrical appliance is safe to use. It consists of a visual inspection and physical inspection of polarity, fuse rating, insulation resistance and functionality.
Although there is no current legal requirement for PAT Testing to take place; we highly recommend that appliances are tested to prevent danger at least every 12 months (Some specific appliances like computers are recommended for test every 4yrs). This is especially applicable to business owners and landlords.