A mistake by financial officers has meant an Oxfordshire council has £924,000 less than it thought.
Vale of White Horse District Council admitted an error meant its reserves had been overstated by £707,000.
It also said accounts for 2008/9 mistakenly counted £217,000 extra from central government.
The council said the shortfall has been partially offset by the spending in 2008/09 being less than anticipated but it would have to save £700,000.
Tony de Vere, the leader of the council, said services to the public should not suffer.
"There's been a marginal adverse impact on some services this year, but really that's been unnoticeable to residents as we've continued to deliver our front line services."
He said if the council could not make up all of the £700,000 this year it may carry over a deficit to the 2010/11 budget.
The issue was due to be discussed at a council meeting on Wednesday night.