Notifiable work - all contractors or only the main contractor to notify? Health and Safety in Employment Regulations 1995
Regulation 26 Notification (part)
(1) In this regulation, the term employer includes a person who controls a workplace.
(2) Subject to subclause (4), every employer who intends to commence any notifiable work or any work that will at any time include any notifiable work must, so far as is reasonably practicable, take steps to lodge notice of that intention in accordance with this regulation.
My view is that 'employer' equal PCBU and that by applying that Clause requires "every employer to lodge notice.