“Exciting times,” tweeted Norwegian Tax Commissioner Hans Christian Holte from Paris last weekend.

The occasion was a meeting of the Organisation for Economic Co-operation and Development at its headquarters, where 129 countries in the OECD and the Group of 20 industrial and emerging-market nations signed a shared plan to combat aggressive tax planning in the digital economy. Today, many international companies exploit legal loopholes and the lack of international cooperation to move profits between several countries, before they finally end up in tax havens.

In 2015, OECD estimated that the loss of revenue resulting from this type of tax planning, what economists call base erosion and profit sharing, totaled as much as $240 million, or approximately 10% of global corporate tax revenues.

In the digital economy, it is particularly the so-called GAFA companies, Google, Amazon, Facebook and Apple, that are creating the headaches. They are all among the world’s largest companies, and today they pay extremely little in taxes in the markets in which they operate.

This is problematic in several ways:

• Companies that conscientiously pay their taxes lose in competition with companies that pay little or nothing in taxes;

• The countries that GAFA companies operate in lose out in revenues. This is especially dramatic for low-income countries, which are further weakened in their fight against poverty; and

• Trust in the tax system is weakened.

The resolution that was signed before the weekend stakes out a course in two directions: One concerns the issue of where taxes should be paid and what percentage of profit should be taxed where a company is located. The other concerns developing a system that ensures international companies pay a minimum tax, so that it becomes less tempting to move money between various countries to achieve tax advantages.

The most remarkable thing, however, is the timeline.

The goal is a consensus on a concrete and long-term international solution before the end of 2020. This is extremely ambitious, especially considering that Ireland, the Netherlands and others profit from the current system. It is nonetheless achievable, simply because those who are not served well by today’s regime are highly impatient. On the other hand, it could be a problem that many are working toward their own national solutions because they cannot afford to wait.

The more that national solutions emerge, the more difficult it becomes to agree on — and to implement — international agreements.

So, these are exciting times. Holte is right about that. For the GAFA companies’ tax attorneys, it must indeed be a little exciting to see the net beginning to tighten. But this is only the beginning.

2019 is exciting. 2020 will be a thriller.