Analysts at UBS predict that an independent Scotland will be unlikely to have a currency union with the UK, meaning deposits would flow out of the country.
The Swiss bank said that if “there is even a possibility that Scotland could have anything other than full monetary union”, then “aversion on the part of depositors may lead to savings shifting rapidly”.
In a research note on Scottish independence, UBS said bank accounts in Scotland would have to offer higher returns to prevent savers withdrawing their funds.
The Treasury previously said that Scotland would not stay part of the Sterling Monetary Framework in the event of a Yes vote, meaning the Bank of England would not be a lender of last resort to Scottish banks.
The UBS report drew parallels with the breakup of Czechoslovakia in 1993, in which savers drained deposits from Slovakia in favour of the safer Czech Republic, and Quebec’s 1995 referendum on independence from Canada.
Although Quebec did not vote for independence, deposits shifted out of the province around the time of the referendum in the Canadian region, UBS said.
UBS said savings flowing south in the event of a split could boost Britain’s economy, while shrinking Scotland, with significant consequences for both countries’ debts.
UBS said both Lloyds Banking Group and Royal Bank of Scotland would be likely to have to move south in the event of a vote for independence, due to the UK Government’s stakes in the banks.
“Politically it does not seem feasible to us that banks like RBS or Lloyds could remain Scottish companies,” it said.