Despite the appearance of utter confusion, there are actually a few things that can be said with some conviction about the result of the UK referendum.

First, for Australian businesses, the main game is probably not tax though tax will play a part in how they respond to Brexit. Other issues are likely to be at the forefront of people’s thinking: the ability of non-EU firms to operate in highly regulated industries (think, banking, funds management, insurance, media, etc), greater barriers to fund-raising cross-border, having to meet FIRB-style restrictions for some types of foreign investment, problems restructuring European operations, difficulties and cost in importing and exporting capital equipment, tax and tariff barriers to cross-border trade, having to demonstrate compliance with EU product standards, problems seconding staff between offices, and so on.

But tax will also matter and the window has started closing on ensuring a tax structure that will handle a post-Brexit world. Whether it will finally shut in 6 months or 2 years is unclear, but it will shut.

Australian companies with branches or subsidiaries in the UK, which source inputs and deliver outputs only within the UK, and have no plans to change that model, can probably stop reading now. But Australian companies which use the UK as the beachhead into Europe, or which have UK operations under a European entity, or might do so in the future will need to think about the tax consequences of their current structures and transactions. For example, corporate groups will soon not be able to rely on the Parent-Subsidiary Directive and the Interest and Royalties Directive to reduce high source country withholding taxes when repatriating profits or paying expenses. And there is a limited opportunity to fix things using European wide exemptions like those provided by the Mergers Directive to deliver a low-tax-cost restructuring of European operations involving the UK.

Perhaps the best news for Australian companies with UK operations is that the UK government is clearly keen on attracting business to the UK: no doubt in response to the prospect that firms may otherwise emigrate from the UK the chancellor of the Exchequer announced last weekend that the UK will reduce its corporate rate to 15%. There are also signs that other fiscal, regulatory and other measures designed to ensure that the UK remains "open to business" may follow suit before too long. On the other hand, such ‎measures might be seen by European governments as an attempt to turn the UK into a ‘tax haven,’ a label which the UK press has already invoked. And if the Europeans decide to retaliate, and then pressure the UK into a quick exit, things may turn very ugly very quickly.