Tax commissioner Chris Jordan has called time on the "delay and obstruction" tactics of a group of international companies who are trying to avoid paying their taxes, saying they could now face court action.
Mr Jordan has taken aim at 26 companies being reviewed under the new multinational anti-avoidance laws, saying they are "gaming the system".
"Enough is enough," he told a Senate estimates hearing on Wednesday.
These companies had pushed the envelope beyond reasonableness, forcing the ATO to draw a line under protracted negotiations which may result in court action.
Some of these were foreign companies that argued they had no tax liability in Australia.
These companies were given 90 days' notice to produce necessary documentation to back their claims, only then to make a variety of excuses for a further delay.
"It's just gone over the top," Mr Jordan said.
"How is it possible that companies known for their new-age technology and innovative products and services fail to be able to furnish us with basic reports," he said.