Halfway through the Government's financial year its deficit at just under $1 billion was $381 million smaller than forecast last December.
That is two-thirds of the full-year deficit of $572 million the Treasury forecast in the half-year economic and fiscal update.
The positive surprise was on the revenue side, the tax take for the six months to December 31, 2014 running 1 per cent, or $323 million, ahead of forecast.
Finance Minister Bill English still professes confidence the surplus will eventuate this year.
But officials warn the largest part of the extra revenue - $132 million more GST than expected - may not hold up for the rest of the year.