There are several main pain points :<p>- companies need to be treated as &quot;unitary&quot; - that is passing profits around internally should not affect the tax paid<p>- profit is the least definable of all measures.  Revenue is something companies don&#x27;t like to lie about.<p>- this change will have to come to small and even consumers to be fair (my wife and I are a unitary item ? Can we share tax allowances?)<p>- even if we decide on treating companies as one black box, choose a better metric to tax on (revenue, dividends) we still do not have a formula for distributing across national borders.  Should the US get all Facebooks profits? No.  Should Facebook pay UK based on number of UK users it has? Doubtful. So ....<p>We are not going to see this end well - unitary treatment seems obvious but a international agreement on how to divide tax will need another two world wars to sort out.