> Countries would simply not agree to play along, no? You require them to play along, you sanction them if they don't, and you penalize anybody locally who doe

> Countries would simply not agree to play along, no? You require them to play along, you sanction them if they don't, and you penalize anybody locally who does any business with the companies who are 'based' there. The EU maintains a current list of "non-cooperative tax jurisdictions", and applies these kind of rules today: https://en.wikipedia.org/wiki/European_Union_tax_haven_blacklist https://en.wikipedia.org/wiki/European_Union_tax_haven_black.... If the global tax changes being discussed come to fruition, I'd expect that list to extend and the penalities involve to tighten up a whole lot further.