Which of the following establishments in the UK is least likely to have to pay the digital services tax?

In what amounts to a shot across the bows for US tech firms, the UK government has announced a new 2% "digital services tax" on their revenue, rather than their profits.
        Concerned that many such companies book their profits in lower-taxed countries outside the UK and keen to be seen to be doing something about it, chancellor Philip Hammond suggested that the tax would apply to profitable firms with global revenues of at least 500 million pounds.
        "Digital platforms delivering search engines, social media and online marketplaces have changed our lives, our society and our economy, mostly for the better. But they also pose a real challenge for the sustainability and fairness of our tax system; the rules have simply not kept pace with changing business models," he said.
        "It is clearly not sustainable or fair that digital platform businesses can generate substantial value in the UK without paying tax here with respect to that business."
        As envisaged, the tax would apply to firms such as Facebook, Google, Twitter, Apple and Amazon, as well as the likes of AirBNB and Uber.
        Hammond said the levy would not take the form of a sales tax on goods ordered online, as this cost could then be passed on to the consumer. Instead, it will "apply to revenues from those activities that are linked to the participation of UK users". He added that he expects to raise around $512 million per year, with US companies taking up about 50% of the total.
        However, the plan is a lot less settled than it might at first appear. The tax isn’t set to come into force until April 2020, with Hammond saying that the government plans to consult on the detail in the meantime.