Sydney's property boom has supercharged NSW government revenues, with stamp duty revenue jumping 50 per cent or $500 million over winter compared with last year, potentially putting the government in a stronger fiscal position before the election next March.

The boom raises the possibility of returning to surplus a year early.

Good news for the government: Premier Mike Baird. Credit:Edwina Pickles

Figures published by the Office of State Revenue show that stamp duty paid on residential property sales from July to September surged compared with 2013-14, with $1.5 billion derived from nearly 50,500 sales. This compares with just under 48,000 transactions between July and September in 2013-14, which delivered $1 billion in tax receipts.

The revenue boost appears certain to continue into spring with Saturday being the third weekend in a row of more than 700 auctions and the two to follow with more than 800. Low interest rates have fuelled Sydney's property market with the median house price rising 16 per cent over the past year and nearly 4per cent over the winter months.