The Organization for Economic Co-operation and Development Tuesday urged its members to agree to major changes in tax rules for multinational corporations to prevent those firms from using legal but ethically questionable strategies to escape their tax obligations.

"These strategies, though technically legal, erode the tax base of many countries and threaten the stability of the international tax system," said Angel Gurria, secretary general of the Paris-based OECD, which represents rich, industrialized countries, including Canada.

"As governments and their citizens are struggling to make ends meet, it is critical that all taxpayers — private and corporate — pay their fair amount of taxes and trust the international tax system is transparent," Gurria said.

The OECD did not recommend specific changes to tax laws or suggest optimal tax rates but urged governments to come up with "global solutions" that would ensure "tax systems do not unduly favour multinational enterprises, leaving citizens and small businesses with bigger tax bills."

The OECD's statement and its related report into the issue, titled Addressing Base Erosion and Profit Shifting, come ahead of a meeting of Canada's House of Commons finance committee on Thursday to focus on the use of offshore tax havens by both firms and individuals.

The OECD's firm stance on the issue is welcome, said Dennis Howlett, executive director of the advocacy group Canadians for Tax Fairness.

"We're quite optimistic that governments in the OECD are actually quite serious about this now," he said "They want to move very quickly to get an action plan in place, to be adopted as early as June, which is really fast.

"It reflects the fact that many governments — the U.S., the U.K., other European governments — are really in a tight bind with big budget deficits, and one of the main reasons is the bleeding of corporate tax income, so they want to do something about this."

Governments have 'schizophrenic' tax policies

But getting corporations to stop using some of the strategies they employ to avoid paying taxes might not be that easy.

"It's actually really hard to do," said Arthur Cockfield, the Fulbright visiting chair in policy studies at the University of Texas in Austin.

Canada, like every other country, he says, has a "schizophrenic" approach to tax policy, wanting on one hand to collect tax revenue and make treatment fair among all firms domestically but adopting tax rules that implicitly subsidize Canada-based multinational companies.

"They want to encourage them to go global by saving taxes at home and abroad and they have these two competing policies," Cockfield said.

The firms don't have much choice, either, given that shareholders can choose to invest in rival companies that can generate better returns by minimizing their global tax liability.

"They are accountable to their shareholders," said Cockfield.

"They're trying to compete globally. They see all of their competitors doing all of these same offshore tax planning strategies, and so they do the same thing."

Canadians for Tax Fairness, which lobbies for a tax system based on the ability to pay and focused on funding high-quality public services, will appear before the finance committee.

It will press that Canada, too, is a victim, and focus on the practice where large companies sell intellectual property rights to a subsidiary based in country that is a tax haven as a way of transferring profit to low-tax jurisdictions.

Some multinationals pay 5%

"The irony is that Canada subsidizes many of the companies to produce a lot of this high-tech intellectual property in the first place, and then these companies turn around and sell it off to a tax haven subsidiary," Hewlett says.

"It's very difficult to police that."

The OECD report was prepared ahead of the meeting of G20 finance ministers in Moscow this week.

It says some multinationals use strategies that allow them to pay as little as five per cent in corporate taxes when smaller businesses are paying up to 30 per cent.

"Many of the existing rules which protect multinational corporations from paying double taxation too often allow them to pay no taxes at all," the OECD said.

"These rules do not properly reflect today's economic integration across borders, the value of intellectual property or new communications technologies."

The issue is gaining traction especially in Europe, as governments, hungry for money to prop up their struggling economies, accuse internet powerhouses like Google and Amazon of incorporating themselves in low-tax countries.

They say the technology giants are trying to avoid paying hundreds of millions of dollars to countries such as Germany, Britain and France — where most of their European income is derived.

According to court documents, French authorities raided Google's offices in Paris over the summer and seized documents in a tax dispute.

More recently, according to a published report, the French government presented Google with a €1.7 billion ($2.3 billion Cdn) tax bill; Amazon acknowledged one for $253 million.

Facebook is also in the line of fire.

In Italy, the undersecretary of the Economy Ministry revealed during questioning in parliament in December that the tax police inspected Google's books, adding that it found millions in undeclared income and unpaid sales tax.

Using havens not illegal

But there is nothing illegal about the multinationals' actions.

Thanks to the way the European Union is run, companies operating in Europe can base themselves in any of the 27 member states, allowing them to take advantage of a particular country's low tax rates.

By setting up overseas headquarters in low-tax jurisdictions such as Ireland or Luxembourg and shifting the profits out of the countries they've done business in, the online companies have managed to keep down both sales taxes and corporate income taxes on their overseas income.

Google's British chief, Matt Brittin, said in December that the company "plays by the rules set by politicians."

The British Parliament's public accounts committee said Amazon, by accounting for the profits made in the U.K. elsewhere in the EU, paid 1.8 million pounds ($2.8 million) in British tax in 2011, on revenue of 207 million pounds.

In Italy, the government said tax police determined Google had undeclared earnings of €240 million ($324 million) from 2002-2006 and had not paid value added tax of €96 million in the period.

Philippe Marini, the French senator who leads the country's finance commission, estimated France is missing out on some €1.3 billion in taxes from Google, Apple, Facebook and Amazon.

And, Marini noted, that amount would pale in comparison to what they likely owe Germany and Britain where sales figures are even higher.

In a filing last year with the U.S. Securities and Exchange Commission, Apple said it had set aside $713 million US for its 2012 foreign tax bill on overseas pretax earnings of $36.8 billion — a provision of almost two per cent of what it made.

With files from The Associated Press