Internode is about to close its Unwired service, three years after it withdrew the plans from sale.
The ISP resold Unwired until August, 2006, after which it said customers would be supported.
The final day for Internode customers of the wireless internet service is 17 August.
"We've written to the few remaining Internode customers left on an Unwired tail circuit to inform them that we'll be shutting the service down fully by August this year," said Internode managing director Simon Hackett.
Internode offered those affected discounts on its ADSL and a $50 credit on its NodeMobile 3G services.
Hackett said Internode may again resell Unwired.
"We'll be very happy to consider returning Unwired to the Internode service portfolio should [it] be successful with [its] long-mooted, wide-scale deployment of mobile WiMAX services," he said.