Annual cost of NBN to rise to $2.1bn by 2017, says budget office

Broadband network will cost budget $580m in 2016-17 and increase from there, but the final cost won't be known until NBN Co is sold

The annual cost to the federal budget of the government's investment in the national broadband network will grow in coming years.

The cost to the budget in 2016-17 is estimated to be about $580m, a report by the Parliamentary Budget Office released on Wednesday shows.