A council was unable to reclaim thousands of pounds in VAT after councillors failed to submit all their receipts for fuel expenses.
During 2009-10, Highland Council was reimbursed £4,217 in VAT but could have reclaimed a further £4,335.
The figures are contained in a response from the administration to a question from SNP councillor Jean Urquhart.
The director of finance has been asked to remind all councillors to keep all their receipts.
Ms Urquhart is chairwoman of the council's audit and scrutiny committee.
Her letter and the response will go before the full council on Thursday for discussion.