Image copyright EPA Image caption Better Together campaigned for a 'No' vote ahead of the independence referendum on 18 September 2014

The Better Together campaign in the independence referendum has been fined for failing to provide a full and complete report on its spending.

A £2,000 penalty was imposed by the Electoral Commission because the pro-Union campaign did not provide receipts or invoices for £57,000 of expenditure.

The fine has been paid and the commission said it accepted the omissions were not deliberate.

The law requires receipts or invoices for all expenditure of more than £200.

Better Together was a designated lead campaigner in the Scottish independence referendum, with more significant resources and a higher profile than other campaign groups.

The Electoral Commission said it took into account that the responsible person for the organisation made efforts to provide further supporting documentation after the deadline for the report had passed.

'Democratic process'

Better Together paid the fine in full on 12 January, the commission said.

Bob Posner of the Electoral Commission said: "The responsibilities of a registered campaigner in a referendum do not end on polling day.

"Transparency around who spends what at referendums, based on complete and accurate financial reports, is an important part of ensuring that the public has confidence in the democratic process".

Pro-independence blog Wings Over Scotland was fined £750 last year for failing to file complete spending returns, while the Labour for Independence group was fined £1,500 for failing to submit any accounts.

The Communications Workers Union, which backed a 'No' vote, was fined £500 for spending money on campaigning before it was officially registered with the Electoral Commission.