Almost half of small business owners in Scotland think independence would be bad for their company, a new survey suggested.
The research found 48% believed a Yes vote would be a negative step for their firm, while 37% of small business owners said leaving the UK would be a positive move for their company.
The research, carried out by the small business network Ingenious Britain, also found 10% of the 1,000 small business owners in Scotland who were questioned said independence would have no impact for their firm.
More than 90% of small business owners have already decided how they will vote in the referendum, to be held on September 18, according to the survey.
Four out of 10 (41%) of those questioned feel independence may make it less likely for them to be be able to invest in growing their business, while 36% feel leaving the UK would make it more likely they they could do this.
When asked what issues concerned them about having a small business in an independent Scotland, taxation, possible new regulations, currency and EU membership were among those mentioned most often.
But just over a third (37%) of small business owners said they had not had enough details from the different campaigns to allow them to make an informed decision about the impact independence would have on them.
Marlon Wolff, CEO of Ingenious Britain said: "One thing all businesses need, especially small businesses, is certainty.
"There is an indication coming through our research that a sizeable proportion of small business owners have sufficient reservations about the potential negative issues and challenges independence might present to be seriously questioning whether it is really in the interests of their company.
"However, it is going to be a close decision with many reacting against what they perceive to be status quo in which their needs as Scottish businesses are not reflected or taken into account."
Tessa Hartmann of Hartmann Media, a PR and communications company working in the fashion sector, said "uncertainty" surrounding the referendum and any future currency was already having a negative impact on the sector and affecting exports.
She said: "Scotland's long heritage in fashion and textiles has thrived as part of Brand Britain. Remove Scotland from the UK and many of our young designers and fashion companies would become ineligible for much of the crucial support and profile they currently receive from the likes of London Fashion Week and the British Fashion Council."
Rory Haigh, who owns owns Optimum Underfloor Heating in Inverness, said Scotland has different social and economic needs to the south of England.
He said: "We are a small country with a good track record of entrepreneurship that is not currently being harnessed or promoted. The government of an independent Scotland would be far more proactive in doing that and in addressing the everyday needs and concerns of Scottish businesses."
Adell Mitchell, who runs the Live Language School in Glasgow, teaching English to international students, also believes independence could boost her business.
She said: "The UK Government has been taking steps to limit the number of international students that are able to come here to study. The hoops they have to jump through to come here has meant many prefer instead to go to Ireland, Canada, Australia and elsewhere where it is easier for them to get a student visa.
"An independent Scotland would give us a greater control over our own student visas, whilst the SNP's commitment to abolish airline taxes would make Scotland a cheaper destination for both international students and tourists alike. This, in turn, would have a knock-on benefit for the rest of the economy."
A Scottish Government spokesman said: "Independence will provide huge opportunities for Scottish businesses large and small - and we welcome the fact that 44% of businesses who expressed a view in this survey believe an independent Scotland will be positive for them.
"Even with the limited powers we currently have, more than 92,000 premises have benefited from our Small Business Bonus Scheme, saving small businesses almost £167 a year. The scheme is now being expanded to benefit thousands more smaller firms. This is part of the overall business rates relief package which is worth over £590 million in 2014-15."
Michelle Thomson, director of the pro-independence business and economic policy network Business Scotland, said: "Day in, day out Business for Scotland is welcoming new members, business owners who see what an independent Scotland could mean for them.
"Using the powers of devolution Scotland has the most competitive business environment in the UK thanks to a range of measures, like the small business bonus scheme, which mean we are next only to London in terms of securing overseas investment and jobs, due to the fantastic efforts of Scottish Development International.
Member Jil Murphy, of Edinburgh-based marketing and branding company ThinRedLine Design, said: "I reject the statement that small business owners need absolute certainty - everything evolves and changes and we adapt and take calculated risks.
"It's how we differentiate ourselves and grow our individual businesses. With business start ups we've all learned to embrace change which by its very nature entails some uncertainty but it's a crucial element in the pursuit of business opportunity and progress.
"It's common sense that it's the people who live and work in Scotland who are responsible for making the decisions about how to run our own affairs, to shape our society as we choose and confront the challenges of our modern world.
"I wholeheartedly believe if we don't vote Yes in September we will have lost the business opportunity of a lifetime."
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A Better Together spokesman said: "Being part of the UK is good for Scotland's small businesses. Having access to a single market of 63 million people rather than 5 million means there are greater opportunities for Scotland's employers.
"Where is the sense in creating a barrier between Scottish businesses and their customers where none exists today?
"What businesses in Scotland need is clarity from Alex Salmond about what would replace the pound. Would we rush to adopt the euro or would we set up a separate unproven currency?"