Scotland is set to vote on September 18 on whether to sever its 307-year-old ties with England and break up the UK with latest opinion polls showing that the race is too close to call.
More than 130 business leaders recently signed a letter calling for the UK to stay together, while about 200 business leaders are standing firm on the other side of the debate.
The following are comments of Britain's top companies and firms with operations in the UK on the Scottish referendum:
Royal Bank of Scotland Group warns it "would be necessary to re-domicile the bank's holding company", if Scots vote for separation. RBS also said a 'yes' vote would have implications for its credit rating, taxes and regulation
Ad firm M&C Saatchi says it is keeping track of the referendum as its largest UK client - the Royal Bank of Scotland - may relocate to England if the UK is split.
TSB Banking Group, which is part-owned by Lloyds, says may relocate some operations to England should Scotland vote for independence.
National Australia Bank says contingency plans for its Scotland-based subsidiary, Clydesdale Bank, include moving to England if Scotland votes to end its union.
Part-nationalised British bank Lloyds Banking Group says its contingency plan includes setting up "legal entities in England", if Scotland votes for independence.
BP's chief executive Bob Dudley says he hopes Scots vote against independence because the UK would better provide the stability required for long-term investment in the oil-producing North Sea. He said Scottish independence could cause the company "uncertainties".
Edinburgh-based insurer Standard Life says the referendum would have no impact on dividend payments or its London listing and reiterates it could transfer business to England if necessary.
The head of one of Britain's largest defence suppliers, France's Thales has voiced concerns over jobs and investment if Scotland votes to leave.
If Scots vote to break up the UK, it would cost everybody money, says Tom McPhail, head of pensions research at fund supermarket and financial advisor Hargreaves Lansdown.
Exova Group CEO has cautioned that a vote in favour of a split would result in some short-term uncertainty for its regional business. The material testing services provider says could easily shift its small head-office out of Edinburgh, if needed.
Uncertainty over Scotland's currency arrangements could prompt capital flight, leaving its financial system in a "parlous state", writes Douglas Flint, chairman of HSBC Holdings.
Edinburgh-based John Menzies says to wait for the outcome of the vote to decide whether to make any changes.
UK insurer Prudential says it will continue operating in Scotland and fulfilling its obligations irrespective of the outcome of the vote.
BAE Systems' chief executive says a split could complicate the issue of pension schemes and would force Europe's biggest defence contractor to talk to its major UK customers.
Kingfisher's chief executive says the home improvement retailer's DIY chain, B&Q, would not leave the region in case of a vote for independence.
Oil services company Amec says it has not made any specific treasury planning and will wait for the outcome of the referendum.
Royal Dutch Shell, a key player in the North Sea oil and gas fields off Scotland, cautions that a vote for independence could mean greater uncertainty for the energy industry.
International Consolidated Airlines Group's chief executive, Willie Walsh, says Scottish independence would be "slightly positive" as an independent Scotland could move to eventually abolish air passenger duty. IAG owns British Airways.
Ryanair Holdings' CEO Michael O'Leary supports Scottish government's intentions to abolish air passenger duty if the UK was split.
