To start with, how do you figure out how much profit this completely Australian company made in France? It's not their revenue from France, and all their expens

To start with, how do you figure out how much profit this completely Australian company made in France? It's not their revenue from France, and all their expenses are in Australia. Does the company calculate expenses according to Australian law, or French law? Calculating expenses is complicated, and each country has different rules. You're effectively forcing companies to file full taxes in every country where they have customers. If the company doesn't declare a profit in France, is France going to audit them? They have no presence in France. Multiply this issue for every country where customers reside. This is bad for consumers. Companies are going to choose which markets are big enough for it to be worth the additional burden. If you're from Canada, too bad; we don't sell to Canadians. Australia and France have similar tax rates. This doesn't have much effect on how much tax the company pays; just how much goes to France. We have already have sales tax, which is a much simpler system that taxes revenue, not profit.