Inland Revenue said it will hold off from using information from psychometric tests until a ruling from the Employment Court.
The Public Service Association has launched legal action against Inland Revenue over its plans to use psychometric tests on employees reapplying for their jobs.
Inland Revenue's chief people office Mark Daldorf said the organisation won't be using information from the tests during existing staff selection decisions until a ruling from the Employment Court.
"We have taken this decision with the interests of our staff front of mind, and to continue to provide them with the most certainty as soon as possible about their future at IR," Mr Daldorf says.
"In the meantime, we are proceeding with our selection process for the new positions, many of which are new specialist roles.
"Inland Revenue is committed to delivering on our organisation redesign and transition timetable as planned, and delivering a world-class tax system for all New Zealanders."
The Inland Revenue is planning to cut the number of its staff by around 30 per cent by 2021 as part of its business transformation plans.
Erin Polaczuk, PSA national secretary, said workers, many of whom had been with the IRD for years - were being coerced into taking psychometric tests just so they can reapply to keep their jobs.
"Often these 'new' jobs involve the same work the employees have been doing for many years."
"If you wanted to get a good sense of a person's skills and abilities, it would be more rational to consider the ample information stored within the department from years of performance reviews and evaluations."
Polaczuk said the move was offensive to long-serving staff and may breach the both Treaty of Waitangi obligations and the departments compliance with the State Sector and Human Rights Acts.
The union says originally the IRD made the tests compulsory for all employees, saying that if staff did not agree to the test they would not be considered for a role.
But following pressure from the union it decided to call the testing "optional", though it also cautioned in a letter to employees last week that non-participation "may mean that we have insufficient information that we can rely on to be satisfied of your capability to perform these new roles."
Polaczuk said the testing software was proprietary and expensive, and it was not clear how much taxpayer money would be be wasted on it.
Inland Revenue's Business Transformation restructure aims to modernise and simplify the tax system, but it is being carried out at the same time as a vast redesign of its computer systems.
The PSA considers this a risky concurrence, and has concerns about the integrity of New Zealand's tax system under these cumulative pressures.