If it wasn't apparent before, the logistical and regulatory nightmare of withdrawing from the EU became increasingly obvious this week.
At the heart of 'Brexit', and the source of the most heated debate, is whether to stay in or out of the single market.
Experts say to leave would necessitate not only new trade deals across a spectrum of business areas, goods and services, but also a complete tear-up of the previous rule book.
Separation would require overhaul of how to deal with EU-owned assets, such as pensions and involve a rethink on everything from sugar tax rules, fishing rights and aircraft-landing slots.
BoA Merrill Lynch said it reckons eventually the UK and EU will agree a 'free trade deal' - a tariff free goods trade, possibly with some transition period to the new agreement, but said this did not address the main impediments to trade, such as admin procedures and rules and regulations.
"...it would be inferior to single market membership and economically costly to the UK: we assume the lost trade would detract 2.5% from GDP in the long-run. Non-tariff barriers can particularly affect services trade, in which the UK specialises," said the bank.
Theresa May lays cards on table...or did she?
The Prime Minister reiterated at the Tory conference that Article 50 would be triggered by March, setting Britain on the path to an independent country once more.
But the pound has been on the slide ever since, as currency traders worry the tone she adopted represented a move toward so-called 'hard' Brexit, which would see us leave the single market.
It appears the PM wants ideally to cut a deal where the UK would remain in the single market but limit migration - a suggestion which has been received frostily in Europe.
German Chancellor Merkel said that the UK must accept free movement and that its (Germany's) car business will not dictate the terms of an easier withdrawal for the UK, while France's Hollande has adopted an increasingly hard line , saying the UK wanted to leave and pay nothing. "It’s not possible," he was quoted as saying.
Financial services facing cold reality..
A report this week from lobby group TheCityUK said 75,000 jobs would go in the UK financial services sector (the biggest in Europe) if the UK was taken out of the single market.
In addition, at worst, US$13bn would be lost in tax revenue if banks, funds and insurers were to lose key passporting rights allowing them to trade with the bloc.
Head for the Highlands?
Scotland is also set to feel the pain of a 'hard' Brexit, said a Thinktank this week, with the loss of up to 80,000 jobs and a reduction of GDP by £8 billion.
The Fraser of Allander Institute however reckons there will be a wave of migration into Scotland post-Brexit because the impact will be even worse in the UK.
IT investment under threat..
In a look at the uncertainty to come, heavyweight broker UBS downgraded this week both recruiter Hays (LON:HAS) and outsource specialist Capita (LON:CPI).on the possibility of a severe cutback in IT spending post–Brexit.
UBS surveyed IT buyers across the UK, France and Germany to gain insight into how B2B (business-to-business) service spending might be affected post-referendum.
It says 22% of companies are planning hiring freezes, 20% plan to use fewer IT consultants, and 39% of IT projects are being delayed or cancelled.
Businesses more confident than pre-vote
But on the flip side, one report this week actually said UK businesses in September were now more confident than before the Brexit vote (arguably, that's because the initial shock has gone and Brexit hasn't started)
44% of business leaders quizzed were said to be optimistic about the UK's economic outlook for the coming year, up from 35% before the vote.
It comes after further positive data service sector data this week- of course key to the UK economy, which showed a sharp increase in September. Construction and manufacturing reported similar gains this week.