See Fair Work Act s.414 and s.443(5).
Before a person engages in protected industrial action they must give notice of the action. The notice must specify the nature of the action and the day on which it will start.
Different notice requirements apply to employee claim action, employer response action and employee response action.
The purpose of the notice requirement for employee claim action is to give the employer the opportunity to respond to the action by making relevant preparations. The response may involve making arrangements to deal with unavailability of labour, including making appropriate arrangements in relation to customers, suppliers and other contractors. Whether the terms of the notice are adequate may depend on the nature of the employer's operations including their size, the number of employees, the number of locations, the time at which the action is to occur and the employees potentially taking the industrial action.