Governments across the developed world have been working to clamp down on tax avoidance by multinational companies.
But a number of recent high-profile cases serve only to highlight the uphill battle they face.
On Wednesday, more than 30 countries in the Organisation for Economic Cooperation and Development (OECD) signed an agreement to share information about multinationals in a push to boost transparency on taxes.
Under the agreement, multinationals will have to report how much they make and what they pay in tax, country by country.
The move follows the release of an OECD blueprint last year targeting the practice of profit shifting - when a company moves profits from the country where they were made to a second location where taxes are lower, so as to minimise its overall tax bill.
A day later, the European Commission set out its own proposals to battle tax avoidance within the European Union. These were aimed at harmonising tax standards across all member states.
On paper, these are good steps towards ensuring that multinationals cannot take advantage of differing tax regimes to avoid paying taxes in full. In practice, however, results have been middling, with multinational giants and their creative accountants proving to be as nimble and slippery as ever.
Take Britain, which used the OECD's new guidelines as a basis to cut a deal with Google, under which the Internet giant agreed to pay £130 million (S$265 million) in back taxes.
The amount, agreed on after an audit by the British tax authorities, is meant to cover claims for the decade from 2005.
Yet few are applauding Britain for the settlement. Opposition politicians have not only criticised the government's handling of the case, but have also called on Google to face a grilling in Parliament over the amount, which they described as derisory.
The deal brings Google's total tax bill in Britain for 2005 to 2015 to around £200 million. But according to a Reuters calculation, the £24 billion of revenue the firm generated in Britain during that period should have generated a tax bill of almost £2 billion.
Google pays less tax because its European profits are channelled to Bermuda.
It was the same strategy for which Apple was under investigation in Italy before it agreed last month to pay €318 million (S$493 million) in back taxes.
The Italian tax authorities had accused the iPhone maker of failing to pay taxes to the tune of €879 million between 2008 and 2013, mainly by booking profits generated in Italy through its Irish subsidiary.
Such cases highlight not only the challenges that regulators face in trying to wrangle back the taxes owed to them by multinationals, but also the tensions simmering beneath their relations with each other.
The EU last year accused Ireland of letting Apple shelter profits worth tens of billions of dollars from the relevant tax authorities, in return for maintaining jobs.
The EU regulator has also had its eye on the Netherlands and Luxembourg. Last year it ordered the authorities in both countries to recover up to €30 million each from Starbucks and Fiat Chrysler respectively, saying the tax deals they had cut with the two firms were illegal.
The deals "endorsed artificial and complex methods to establish taxable profits for the companies" that "do not reflect economic reality", the EU said. Not surprisingly, both the Netherlands and Luxembourg disagreed with the ruling.
And then there is the United States - home to many of the world's multinationals. It, too, has been trying to get its companies to pay their taxes in full. Given the 40 per cent corporate tax rate in the US, not many multinationals find the idea appealing.
So the US is concerned that the deals being cut between US multinationals and European countries will bite billions of potential tax revenues from its own coffers.
In response to Europe's moves, the US Senate is urging the Treasury to double-tax European companies. At the same time, the US is also struggling to keep up with the many creative ways that its companies are skipping on tax payments.
One practice that has been in the spotlight is "inversion", in which an American firm re-incorporates itself in a low-tax location while still maintaining operations in the US.
The most recent case featured Johnson Controls, a US maker of car batteries, which took over Ireland-based Tyco International for US$16.5 billion (S$23.5 billion) - a manoeuvre that US politicians quickly denounced as being largely aimed at reducing Johnson's tax bill.
After the merger, Johnson said it would move its headquarters to Cork, Ireland. Since the news broke, US presidential hopefuls have jumped to criticise the firm and call for comprehensive tax reform.
Drug giant Pfizer structured such a deal with Irish firm Allergan in November last year.