Windfall taxes (also known as one-time-only taxes) are designed to address periods of perceived excess profits or income. Generally, assessing a windfall tax is rooted in the belief that during particular periods of economic expansion, some companies or industry sectors receive a disproportionate and unjust share of income and/or profits. Therefore, there is a belief that these excess gains should be redistributed more equitably through still imposing tax on companies’ profits – hence, a surcharge or windfall tax.

Windfall taxes are one of the most politically contentious areas of taxation across the world, with fierce debates on whether the levies are fair. Proponents of Windfall taxes strongly suggest that these taxes serve to redistribute the fiscal rewards of economic expansion more equitably, and as a result, aid progress in the wider economy by injecting funds into government initiatives such as education and health care. In addition, proponents see windfall taxes as a way to prevent companies or sectors from becoming too large and too powerful due to a sudden period of success or a specific event.

Opponents of the windfall tax react to such taxes on the basis of market efficiency, arguing that windfall taxes are not effective tools for leveling the economic playing field and pointing out that such taxes can be seen as punishing success and discouraging businesses from making investments into the economy. Particularly, they argue that these levies simply serve as government funded ‘bailouts’, without due consideration of the economic implications of such levies.

In spite of this ambiguity, windfall taxes are continuing to be levied across the world where there is perceived inequity. For instance, recently a number of countries have imposed fairly hefty windfall taxes on the digital industry—including the UK, Spain and France —suggesting a degree of consensus that some of the large corporations within the sector have achieved success due to overly generous terms and conditions from governments, to the detriment of their local economies. In their respective strategies, the countries have asserted that their motivations behind charging these taxes is to ensure a fairer system of taxation.

Overall, windfall taxes remain an emotive tax system and one that generates mixed opinions around the world, particularly on the motives for the taxes. However, regardless of these debates, one thing is certain – it is not a tax system that will be declining in frequency any time soon.