The official result will be announced later in the day.
With results of 30 out of the country's 32 council areas being declared, the "No" -- those against independence -- have an unassailable lead of 1,877,252 votes to 1,512,688, the BBC reported.
Ninety-seven percent of the 4.3 million people eligible to vote Thursday registered to do so, and turnout was estimated at more than 80 percent.
The polls closed at 10 p.m. and the first official results were not expected until after midnight, with the final tabulation coming at around 7 a.m. Friday.
YouGov interviewed 1,828 people who cast their ballots at polling places and 800 others who voted by mail.
The 'No' campaign won the Scottish independence referendum to keep Scotland within United Kingdom, polling results showed.