More Kiwis moved to Australia in the last 12 months than people arrived from across the Tasman, ending two years of net inflow to New Zealand.
New Zealand Institute of Economic Research economist, Christina Leung, says after more people moved here after the mining industry slowed and New Zealand's economy strengthened.
But she says the Australian labour market has picked up, and Kiwis are recognising that in their search for better prospects.
Net migration figures had been bolstered by a reluctance of Kiwis to shift across the Tasman as Australia's economy went through a downturn and New Zealanders lost access to certain government supports. However, figures released on Friday show an annual net outflow to Australia of 66 people in September, the first annual net outflow since September 2015. The number of people moving to New Zealand from Australia shrank 3 per cent in the year to September 30 from a year earlier, while departures rose 5.2 per cent.
ASB Bank senior economist Mark Smith said in a note that the "improving Australian labour market, if sustained, could further slow net immigration via triggering increased PLT (permanent long-term) departures across the ditch."