Around 1500 full-time jobs are set to be impacted as the Inland Revenue Department upgrades its ageing systems over the next eight years.
Some positions will be transformed while others made redundant as part of the IRD's Business Transformation project, it was announced today.
About 90 percent of IRD staff will experience some changes in their position but job security remains the main priority according to PSA national secretary Erin Polaczuk.
"The IRD's committed to helping staff through the transition - including re-skilling for their existing roles or upskilling for new, more demanding jobs," she said.
"It's inevitable jobs will go, but we are committed to retaining as many as possible."