The IRD established a concession arrangement after winning the so-called "Penny and Hooper" tax avoidance case, involving two surgeons who changed their personal arrangements to coincide with the introduction of a higher personal tax rate in 2001.
That arrangement is now being extended to March 31, 2013, in anticipation of further voluntary disclosures by taxpayers who otherwise may face tax avoidance probes.
The New Zealand Institute of Chartered Accountants (NZICA) said in a media statement that the extension would give its members certainty about how the Penny and Hooper decision affected them and their clients.
It would also give NZICA time to inform its members and to encourage them to make voluntary disclosures where appropriate, said Frank Owen, NZICA's acting tax director.
"This will provide clarity to both our members and IRD," he said.
"We will be working closely with the IRD to promote this decision with our members and to make sure that our members have all the answers they need."
Ernst & Young tax partner Jo Doolan said until now, the IRD's offer had lacked clarity around when the offer would expire.
"Today's offer draws a line in the sand for taxpayers," she said.
"But it is limited only to those who have not already received a letter from the IRD notifying them that their tax position is being reviewed."
Revenue Minister Peter Dunne, the IRD and NZICA were to be congratulated for their proactive approach but taxpayers would be justified in having "a sour taste in their mouths", she said.
Before other taxpayers "rock up to the tax confessional" they should consider all facts and circumstances outlined in the Penny and Hooper case.
"There is still too much focus on an ambulance at the bottom of the cliff when it comes to tax administration.
"The way the IRD continues to try to rewrite our tax laws by applying the anti-avoidance rules undermines the integrity of the tax system and leaves one with the feeling the Revenue is trying to squeeze the last bit of toothpaste from an already-empty tube."
Struggling businesses do not need to be side-tracked by engaging in a lengthy battle with the tax office, she said. The amount of tax at issue was unlikely to outweigh the cost of an ongoing tax dispute.
"For that reason, the latest offer from the IRD is welcome and needs to be taken seriously by all those who could be impacted. But you do not automatically have a problem. Take advice first."
- nzherald.co.nz