With just two days to go until Scotland votes on independence, Scottish entrepreneur and philanthropist Sir Thomas Hunter told CNBC on Tuesday there are still key facts missing from both sides of the debate.
One of the biggest questions is what currency will be used if Scotland becomes independent, he said.
"It's huge. It's fundamental and it's so important to businessmen," Hunter, who's been called Scotland's first homegrown billionaire, said in an interview with "Power Lunch."
"We still don't know if we vote yes, are we going to get a currency union with the rest of the U.K. or if that's not going to happen, what is plan B."
On the other side of the debate, while London has pledged to give Scotland extra powers if it stays in the U.K., there is still a lack of details about what that added authority would be, Hunter said.
To help citizens become more informed about what's at stake, Hunter's foundation has published an e-book called "Scotland's Decision," which tackles 16 questions voters should consider before making a decision.
"This is an important question for Scotland, probably the biggest political decision we'll make in my lifetime if not for the next 300 years. Therefore, I knew it was crucial that we didn't leave it to the politicians alone to inform us."
Hunter has already voted on the issue in a mail-in ballot, but he would not divulge whether it was yes or no.
However, Hunter tipped his hand on two important issues.
"Staying with the pound sterling in its current form is a big plus for business. We know the risk. We can quantify the risk. We can manage the risk," he said.
A "yes" vote is "moving a bit into the unknown and therefore the unknown ups our risk, ups our cost."
There is also uncertainty surrounding what will happen with the financial institutions based in Scotland.
"Financial services is a really important industry," Hunter said. "I would want to do everything in our power to keep and let the financial services industry flourish."
"I don't know what it means for jobs but it's just more uncertainty," he added. "I'm against uncertainty."
—By CNBC's Michelle Fox