New Zealand Post says it will axe 80 to 100 corporate roles at the state-owned company's Wellington and Auckland offices by July.
Spokesman John Tulloch said the restructuring would provide cost savings and also right-size the firm, which has faced a sharp decline in mail volumes, to meet the current business conditions.
"At New Zealand Post there were probably some vestiges of the past there and it's a case of making sure we've got a corporate structure for a very rapidly evolving, changing market," said Tulloch.
The job cuts will affect roughly 6 per cent the company's 1340 corporate staff.
Tulloch said the majority of the job losses would take place in Wellington.