The increasingly border-less global economy means big firms often have no tax liability in a country, even with a major local presence, Assistant Treasurer David Bradbury said on Wednesday.
In Australia, multinationals including the local arm of Google have been accused of shifting income to countries such as Holland or Ireland where tax rates are lower. Neither Google nor Apple could immediately comment when contacted by Reuters.
"This should not be a guessing game," Bradbury told Reuters after releasing measures that would require about 2,000 large and multinational businesses, including miners BHP Billion and Rio Tinto with yearly revenue of a $100 million ($104.60 million) or more, to have their tax details published by the government.
"The government intends to improve transparency around how much tax large enterprises are paying. We want to make sure that large multinational companies are paying their fair share," he said.
Australia's minority Labor government last year released draft revisions to tax laws to stop profit shifting in line with a push by Britain and Germany, and discussions last year within the Group of 20 wealthy nations.
Asked in a radio interview on Wednesday about alleged profit shifting by Google, Prime Minister Julia Gillard said she did not want to single out any company but said profit shifting was an international issue requiring action by G20 nations.
"As a matter of principle,taxpayers, whether they're companies or individuals, should pay their proper rate of tax," Gillard said. "This is an ongoing discussion at an international level."
The revisions, opposed by opposition conservatives, will be voted on by parliament after the May 14 Budget, with the government requiring support from a handful of independent lawmakers and Greens holding the balance of power.
The amendments aim to shut down loopholes that risk the loss of more than a $1 billion in government revenues each year by allowing IT firms to avoid or reduce tax through online sales.
Australia's corporate tax rate is 30 percent, compared with Ireland's rate of 12.5 percent. Some major companies including Rio Tin to have already begun publishing tax details, expanding on information in existing financial statements.