who is responsible
  for PAT Testing ?

The Provision and Use of Work Equipment Regulations 1998 (PUWER) requires, every EMPLOYER to ensure that work equipment is suitable for the purpose for which it is provided, only used in the place and under the provisions for which it is provided.

It also requires every employer to ensure work equipment be efficiently maintained and kept fit and suitable for its intended purpose. It must not be allowed to deteriorate in function or performance to such a level that it puts people at risk. This means that regular, routine and planned maintenance regimes must be considered if hazardous problems can arise.

The Regulatory Reform (Fire Safety) Order 2005 states that the responsibility for compliance rests with the responsible person. In a workplace, this is the employer and any other person who may have control of any part of the premises, eg the manager or owner.