EU border decision
An international border is one of the things worried about by those who oppose the break-up of the union. If there is a "yes" vote, those who oppose independence worry about what Scotland will lose in leaving the UK, with currency the most discussed subject.
In the event of a "yes" vote, the Scottish government wants to stay in a currency union with the new UK of England, Wales and Northern Ireland, under which both countries would use the pound and share control of its monetary policy, including the setting of interest rates.
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But all three main Westminster parties have ruled this out, and while Scotland's first minister Alex Salmond says they are bluffing, he adds that he has three "plan Bs": Scotland could use the pound without a say in its control, adopt the Euro single currency or set up its own currency.
M8 Group, an e-commerce firm which runs PetsPlanet.co.uk and GreenFingers.com from Livingston in West Lothian, plans to move at least 35 of its 98 jobs south of the border if there is a "yes" vote, with currency issues among its reasons.
"If you're a business in Scotland serving the UK, which pretty much any dot-com business will be, you change from serving a domestic market to being one that is 90 per cent export," in the event of independence, says founder and chief executive Kevin Hague. "I find it hard to believe that most e-commerce businesses wouldn't draw the same conclusion."
Hague, a signatory of a pro-union newspaper letter, says his firm could handle different currencies but with higher transaction costs and risks: "You've got your costs in one currency and your revenues in another."
He also thinks EU membership status on both sides of the new international border would be problematic. The Scottish government wants an independent Scotland to be in the EU, but this may depend on it being accepted as an existing member rather than a new applicant - and other EU members such as Spain are trying to discourage their own independence movements. That said, there is the chance a Scot-less UK would leave the EU if the Conservative party wins the next Westminster general election. "Either way round, we're trading across an EU border," says Hague.
Clearly there are diverging opinions over how independence would affect Scottish ICT firms, and the same is true for Scotland's ICT-reliant businesses. But there are perhaps greater reasons for ICT professionals to be concerned, particularly in the area of financial services.
"The problem [for banks] comes down to the uncertainty generated by living in a new country combined with concern over the possible loss of the British pound and the withdrawal of the safety net they are afforded by Her Majesty's Government should things get sticky again.
Scotland's oil, gas and whisky industries are unlikely to go anywhere, and ICT-reliant contact centres, which employ 155,000 people in Scotland according to ContactBabel, work happily across international borders.
Emblematic of these is broadcaster Sky, whose main UK contact centre is one of those employing so many Scots, up in Livingston; it says it will not speculate on the vote but a spokesperson has indicated the firm won't leave an independent Scotland.
"We like being in Scotland, having been there from the very start of the business 25 years ago. We provide home entertainment and communications services to around 40 per cent of Scottish homes and have more than 6,400 employees based in Scotland. We have no current plans to change that," the spokesperson told us.
But things are different in the financial services sector, and as a break-up has started to look possible, they've started to speak out and say what steps they will take in the event of Scotland leaving the UK.
The problem comes down to the uncertainty generated by living in a new country combined with concern over the possible loss of the British pound and the withdrawal of the safety net they are afforded by Her Majesty's Government should things get sticky again, like they did in 2008.
Currently, if a Scottish-based bank threatens to collapse, it can be saved by the UK authorities - as happened to both the Royal Bank of Scotland and HBOS during the crisis six years ago. The UK struggles to manage such rescues, with a financial sector with assets around five times the size of the economy. An independent Scotland's finance houses would have assets 12 times the size of its economy.
In a crisis, it would have to pick up the pieces on its own, unless Westminster politicians changed their minds over a UK-Scottish currency union. However, this would mean convincing the voters of England, Wales and Northern Ireland that pouring money into a foreign country's banking system would represent a good use of their taxes.
That leaves the plan Bs, all of which involve Scotland's financial companies working under a different regulatory regime to the new UK's. That may not matter too much for firms with an international customer base, but those serving the current UK-wide market would fear customers from England, Wales and Northern Ireland withdrawing business as a result.
Several Edinburgh-based finance houses look set to shift some operations south of the border in the event of a "yes" vote, meaning the city will lose a significant portion of its financial services industry.
Standard Life employs around 5,300 of its 8,500 staff in Scotland, but does just six per cent of its business there, compared with half in the rest of the UK.
Standard Life on Wednesday said it would transfer parts of its operations to the UK under contingency plans it's drawn up should the referendum go against the union.