Telstra Corporation Ltd 0400, 0407-0409, 0417-0419, 0427-0429, 04303-04305, 0434, 0437-0439, 0447-0448, 0457, 0458, 04590-04592Optus Mobile Pty Ltd 0401-0403, 0411-0413, 0421-0423, 04301, 0431-0432, 04350 Vodafone Network Pty Ltd 0404-0406, 0410, 0414-0416, 0420, 0435 (except 04350), 0449-0451, 0424 Hutchison Telecommunications (Australia) Pty Ltd (trading as 'Three') 0424-0425, 04300, 04302, 0433 Virgin Mobile (Australia) Pty Ltd 0466 (Note: Virgin utilises the Optus mobile network, and as such, other mobile operators (Such as Exetel) may also receive numbers in this range) Student Administration Pty Ltd 0488 Currently unassigned 0426, 04306-04309, 0440-0446, 045 (except 0450 and 0458), 046 (except 0466), 047, 048 (except 0488), 049 However mobile number portability means an individual number might have been "ported". There are also many resellers, and many companies buy "air time" from other companies for roaming.