Before a packed public gallery, including family of both the men, the court was told how in their time as directors of accountancy firm Tax Planning Services they used sham transactions to create tax deductions and credits for some of their clients.
The pair filed false income tax and GST returns on behalf of their clients for goods and services that were never provided, giving their clients an invoice for the claim, but receiving most of the payment back.
Their clients' tax liability was reduced, meaning the pair could keep the difference.
Over the course of the five years they claimed fictitious expenses in excess of $9 million, of which they could personally keep somewhere between $1.8 million and $2.3 million.
Skinner personally gained three quarters of the $2.3 million over the five-year period and Rowley gained a quarter of that.
The IRD was underpaid just under $3 million, of which the two men have not paid back anything and it was anticipated that more than half of it would never be recovered.
Skinner spent his gains on travel and accommodation and Rowley used his share to pay off his mortgage.
Skinner was the front man of the scheme who did the talking with the clients, and Rowley did the paperwork behind the scenes.
Clients would be referred on by now deregistered accountant Shaan Stevens who knew the pair would take part in the fraud.
Last November Stevens pleaded guilty to more than 20 charges of fraud tax evasion and attempting to pervert the course of justice and was sentenced to 10 months' home detention and 150 hours' community work.
In sentencing the pair, who have been declared bankrupt in the past week, Justice Kos said when the men realised IRD was after them they counselled their clients into giving false evidence.
"That plan failed because most clients told the truth to the Revenue."
Both men had families with teenage children and Justice Kos said their offending had caused "real hurt and humiliation'" to them.
However, in pre-sentence reports compiled before today both men still denied any wrong doing and a showed a profound lack of insight, Justice Kos said.
Justice Kos rejected submission that the pair were good characters because the offending was pre-meditated and they had never shown any real remorse.
While he accepted that Skinner was the leader in the scheme he said Rowley still played a major role - "not so much pushing the envelope, as setting fire to it".
He did not accept that only Skinner led the "high life", although he did get more of a monetary gain than Rowley.
In a statement following the sentencing IRD group manager of assurance Patrick Goggin said IRD welcomed the sentence of both men - the longest ever handed down in a New Zealand tax case.
"Rowley and Skinner not only breached their clients' trust by acting illegally but also that of Inland Revenue which trusted them to act with honesty and uphold the integrity of the tax system."
The pair crossed a line by coaching their clients to lie to IRD, he said.
"Despite their complex and concerted efforts to cheat the tax system, Rowley and Skinner failed to stay ahead of the law. As a result, they ended up in court, and this sentence shows that Inland Revenue and the courts view such offending very seriously," Mr Goggin said.
