The council has experienced an ‘unprecedented’ level of postal vote applications ahead of the referendum.
Counting officer for the Borders, Tracey Logan said: “The number of postal vote applications, especially those arriving close to the deadline, reached unprecedented levels.
“Due to this high demand the external printing company used by SBC and a number of other councils faced a slight delay in getting this latest batch of postal vote ballot papers issued - but they are still expected to arrive from today so there is still plenty of time to return them by September 18.
“Anyone who was not previously on the Electoral Register and who did not manage to register before the deadline of September 2, unfortunately will not be able to vote. The deadline is set in legislation and applications received after this cannot legally be accepted, whatever the reason for the late submission.”
A total of 14,628 postal votes have been issued in the area for the referendum, with over 2,500 postal voters added to the electoral register since August 11.
Over 2,000 electors have been added to the register since that date.
The total electorate for the Scottish Borders Council area is 95,533.