Also when US says 20%. It means US gets £100. US aint the sharing type :p.
How would this even work with territorial taxation countries such as Singapore/Hong Kong ?
This kind of system will only work within a group of nations that agree that this is a good idea, such as the EU. Ireland and the Netherlands probably don't agree - but can hopefully be forced.
Obviously no countries in the EU have territorial taxation.
Thats why gave this example to show that it does not work as profit remains the same.
Lets assume there is no US Co. Ireland Co is parent company and its only doing business in EU. Then either Ireland [1] allows low tax rates to attract business in which case profit is low and thus UK/France share is low. Or Ireland is high-tax, then business move to another low-tax in EU.
This only work if there is single tax rate in EU. But if there is single tax rate, then why even go this complicated tax calculation route.
[1] Estonia (and in near future Latvia) does not tax untill profit distribution, reducing effective tax rate to 0%.
The "trick", if I understand, is to only care where the final service/product is actually delivered. So in your example the idea would be to ignore France SAS, or rather I imagine to assume Ireland Co and France SAS are one and the same, and tax them "together".
At first glance it sounds very hard to setup (and it certainly is), but that's what is being attempted here. On the other hand it's not particularly complicated to know whom Google is selling ads to, and where iPhones are sold, so there must exist a solution to this problem...
One option, which I've not thought through, would be something like the following:
You make £500 profit.
You pay 20% corporation tax, so that's £100. The question is who does that get paid to?
If 15% of your revenue comes from the UK and 50% comes from France, then £15 of the corp. tax goes to the UK and £50 goes to France.
More complicated with different company structures and corp. tax differences between countries, etc, but I think this may be what they're getting at.