NEXT year's council election could cost Tweed ratepayers $400,000, with up to $75,000 of the costs caused by the recent decision to hold referenda on whether voters want to choose the mayor and increase in the number of councillors.

Council staff have urged councillors to continue to have the NSW Electoral Commission carry out the election, rather than do the work itself, partly because of insurance which would cost $16,000.

The NSW Government gave the councillors were until the end of this month to decide if they wanted to engage the Electoral Commission for the work.

Alternatively they could have the election administered by the council general manager who would appoint a returning officer and follow various other conditions.

Councillors voted unanimously on Tuesday night to stay with the electoral commission but were told that would cost around $400,000.

"The expenditure incurred on the conduct of the 2008 Local Government Election was $336,500," staff said in a report.

"It is estimated that the 2012 Election would roughly equate to this amount plus CPI movement, plus an additional $40,000 to $75,000 would be required to undertake the two constitutional referendum questions."

Those questions are whether residents want to choose a popularly elected mayor for the council term following the 2016 elections and whether they want to increase the number of councillors, also in that term, from seven to nine.