The government has recorded a stronger surplus thanks to a higher tax take and lower spending.
Excluding investment gains and losses, the operating surplus stood at $1,145 million for the seven months to January, compared with the $442m surplus that had been forecast.
The growing economy boosted tax revenue, which came in above expectations at $42.4bn.
The Treasury said the improvement was led by a higher corporate tax take due to rising profits. That more than offset lower than expected GST.
The department said economic indicators pointed to below-forecast growth in domestic consumption and residential investment in the December quarter.
Expenses came in below expectations, down 0.8 percent to $44.2bn.
The Treasury said most of the $338m difference was due to uncertainty over the costs of the Kaikoura earthquakes, which had yet to be included in the actual results.
Kaikoura repairs are estimated to cost between $2bn and $3bn.
The government added $1bn in quake-related expenses to its forecasts, with $685m of that due to EQC claims costs, and the remaining $315m attributable to other things, such as funding local infrastructure.
Treasury is forecasting a $473m surplus in the June 2017 year.
If investment gains and losses are included, the operating surplus is a larger than expected $7,827bn. That was mainly due to an actuarial gain of $3.3bn on the ACC liability, the Treasury said.
Net debt totaled $61.7bn, or 24.1 percent of the value of the economy.