Inland Revenue offices and call centres are set to go offline for a week next month as they implement a key stage of their $1.6 billion Business Transformation project.
The tax department says its myIR online services call centres will close between 3.00pm on April 18 and 8.00am on April 26, reports Stuff.
The offices will not be open to the public between those dates and Inland Revenue are warning that any partially completed online tax returns and messages that is been saved in draft on its website will be lost when the shutdown begins.
Inland Revenue closed its call centres and online service for the shorter period of four days in April last year while it switched systems for an earlier part of the Business Transformation transition.
Commissioner Naomi Ferguson told a select committee last month that the department had taken on an extra 325 call centre workers for up to a year to handle extra phone calls that it expected to result from this year's changes to the tax system.
The Chief Executive of Madison Recruitment Simon Bennett, which employs those workers, says Inland Revenue has requested those contractors take annual leave during the shutdown, but that he has told the department that is not justifiable.
Inland Revenue deputy commissioner Sharon Thompson says the dates for the shutdown have been carefully chosen to cause "the least possible disruption".
"Easter and Anzac Day happens during this period and there are only two full business days within these dates."
Inland Revenue staff had been invited to take annual leave on those two business days "as the main computer systems will be shut down but there's certainly no compulsion", she says.
"Our people who choose not to take leave will be reassigned to other duties such as training on those two days. This invitation was extended to contract and temporary workers as well and it's up to the individual about what they choose to do."
The most visible result of the tax-system changes for most taxpayers will be that from next month, Inland Revenue will begin automatically issuing 1.7 million annual tax refunds and about 115,000 tax bills, without taxpayers having to first fill in forms.
But underneath the bonnet, Inland Revenue is gradually retiring its aging mainframe-based computer system First, which uses Cobol software that has become increasingly difficult to update and support.
The resulting "simplification" of the tax system should mean taxpayers are taxed more accurately through the year, with much smaller end-of-year adjustments, and is expected to see Inland Revenue shed about 1500 jobs by 2021 – with half of those cuts having already been made.