The price of sending an average-size letter is set to rise to $1 from July 1, as New Zealand Post attempts to offset revenue losses from sharply falling letter volumes.
The number of letters sent from New Zealand has fallen by around 60 million items a year according to the postal service, forcing it to adjust prices to combat shrinking revenue.
"This has impacted revenue and despite significant and on-going cost reductions some price adjustments are necessary," New Zealand Post said in a statement on Wednesday.
A medium-size letter sent by Standard Post will cost 20 cents more from July 1, while a FastPost letter will jump by 40 cents to $1.80.
The price of BoxLink, FreePost and Bulk Mail products will also be adjusted.
Domestic parcel prices will remain unchanged in 2016.