New South Wales, Victoria, Queensland, South Australia and Tasmania all sit within the national workplace relations system for private sector employers, so s.15A and the National Employment Standards apply uniformly. The practical variation comes from long service leave, which remains a state matter. Casuals accrue long service leave under the Long Service Leave Act 1955 (NSW) and its Victorian equivalent, the Long Service Leave Act 2018 (Vic), and continuity of service for casuals is calculated differently in each. Victorian employers should note that continuous employment survives breaks of up to twelve weeks under the state Act, which catches out businesses that assume a summer gap resets the clock.
Western Australia is the outlier that matters. Sole traders, partnerships and unincorporated bodies in WA fall outside the national system and sit under the Industrial Relations Act 1979 (WA) and the state award system. For those employers, s.15A does not apply and the casual definition comes from the relevant WA award instead. Incorporated WA businesses are national system employers and follow the federal rules. Check your entity type before assuming the Fair Work Act governs your WA casuals.
Queensland and the Northern Territory raise a portable long service leave issue in construction and contract cleaning, where industry schemes capture casual service that would otherwise be lost between employers. A casual labourer moving between builders accrues through the scheme rather than through any single employer, so your contract should acknowledge the levy arrangement rather than promise entitlements the scheme actually holds.
The Australian Capital Territory operates portable long service leave across a broader set of industries, including community services, security and hospitality. Casual engagement in those sectors carries a registration obligation that the employment contract itself does not discharge. Employers in the ACT hospitality trade frequently miss this, and the scheme audits.