The Work at Height Regulations 2005 were introduced in a bid to prevent death and injury caused by falls from height, therefore minimising risks to workers. Employers, facilities managers, building owners and anyone else that controls work at height, including the self-employed can be held responsible should an accident occur. They would be liable if an accident occurred and the equipment was found to be faulty or uncertified. These individuals and organisations have a legal responsibility to ensure that the Work at Height Regulations 2005 are implemented and that all activity is properly planned, supervised and carried out by competent persons. They are also responsible for ensuring that fall protection systems for Work at Height are inspected regularly, at a maximum 12 monthly intervals, but more frequently when working in hazardous environments.
People

The employer (or organisation that controls Work at Height, such as a facilities management company) is required to take responsibility for certain duties of care under the Work at Height Regulations 2005. The regulations state that the employer must ensure that workers have available to them the appropriate Work at Height equipment, including Personal Protective Equipment (PPE). Workers should also receive appropriate training in the use of that equipment and whilst they are in training with the equipment, they should be properly supervised

Source: https://www.shponline.co.uk/who-is-responsible-for-working-at-height/