The New Year has brought what appears to be a new sense of optimism at the OECD that it might - just might - manage to forge a global consensus on how to tax the big digital companies by the end of next year.

If that seems like a very short time to bring about agreement on a very big and divisive issue, that’s because it is.

But Pascal Saint-Amans, the director of the OECD’s Tax Policy division says the organisation was able to produce agreement on the BEPS (Base Erosion and Profit Shifting) agenda inside a very tight timetable before.

Yes, it’s still a big challenge - and the timetable is much tighter - but in a briefing earlier this week he set out how previous experience might be brought to bear in solving this particular problem.

Building a consensus seems to be the key - both a consensus that something needs to be done (the easy bit) and a consensus on what to do.

That, and a rapid and seemingly profound change of position by the United States.

Because one of the key drivers for change is the Trump administration’s Tax Reforms from 2017, which include GILTI – the Global Intangible Low Taxed Income Tax - effectively a minimum tax rate on US-owned firm’s income from intangibles of roughly 10.5%.

The OECD is now working on a global minimum tax for intangibles, based on the US GILTI approach, according to Achim Pross, the OECD’s head of International Co-operation and Tax Policy.

The Americans need the money to pay for tax cuts introduced in the Trump reform, notably the headline rate reduction.

But other countries are short of revenue too, and have been looking at the ability of big tech companies to pay remarkably little tax with a mix of wonder and rage.

Some, like the British and the Italians, have already moved to extract more from the digital giants.

The European Commission - trying to stop a patchwork of national tax treatments of digital profits spreading across the single market, published its own proposals.

Ireland and a couple of other states have blocked them.

In Ireland’s case, the argument has long been that we prefer a global consensus driven by the OECD’. But be careful what you ask for - that global approach may come about, and quite quickly too.

And at its heart is a pretty radical shake-up of ideas that have been long established in international tax treaties.

Which may well lead to the re-allocation of some taxing rights based on where digital services or products are consumed, not where they are administered from.

Or tax rights may be allocated according to the use of the intangible "marketing" that is applied to sell a product or service in a particular market.

Either way the direction of travel appears to be away from low tax countries that play host to Intellectual Property management companies, and towards an allocation of tax based on where that intellectual property meets the data that generates profits.

And the big data is found in the big markets with big populations.

The scale of the consensus extends far beyond the OECD - the club of rich developed countries - and the G20.

During the week a document was published in the name of the "Inclusive Framework", which brings together 127 countries in the developed and developing world (where Corporation Tax provides a much bigger share of government revenue than in the developed world).

It’s this diverse group, the Inclusive Framework, that has given its backing to a method of forging consensus, devised by the OECD.

Essentially, they have taken four proposals which will be focused on between now and the end of 2020 in an effort to arrive at what needs to be done on "the Tax Challenges of the Digitalisation of the Economy".

As usual in these kinds of things, there is talk of "pillars" - only two for the moment.

The first pillar focuses on the challenges the digitalising economy poses to tax authorities, and how taxing rights might be allocated in future.

The second pillar looks at the remaining issues from the BEPS agenda.

The two overlap, as digitalisation is going on in virtually all types of businesses - it is not confined to digital companies like Google or Facebook; look at automobile companies and how they and their products gather and use data (to take but one example of a "traditional" industry that is changing fast).

These are big, profound changes in the world if international taxation, but judging from the timetable outlined by the OECD during the week there seems to be a view that a window of opportunity now exists to get broad agreement on making some pretty big changes that Pascal Saint Amans says will "go beyond the arms length principle" that has guided corporate tax treaties over most of the last century.

They also, as the document published by the Inclusive Framework last week notes, "go beyond the limitations imposed on taxing rights determined by reference to a physical presence generally accepted as another corner stone of the current rules".

Countries will still be free to set their own tax rates. Ireland’s world famous 12.5% rate - surely now as much a part of the national brand as Shamrock and Aran Sweaters - will be there as long as the Irish want it.

But what is left to be taxed at 12.5% may change dramatically, as might the attractiveness of Ireland as a location for certain types of investment.

The OECD is going to publish a consultation document the week after next, and open it up to comments for a three week period, ahead of a conference on the topic in Paris in March.

So if international tax is your thing, get ready to make your contribution - time is short.

The work of the consultation and conference will feed into a meeting of the Inclusive Framework group at the end of May, which aims to report to the G20 Finance ministers meeting in June with an agreed way forward.

Getting the nod from the G20 would set in motion 18 months of in-depth work, targeting a final report at the end of next year, meeting the terms of the 2017 mandate to come up with a plan for taxing the digital economy by then.

Ambitious - certainly. But the sense of energy and optimism from the OECD staff is tangible.