The government's bright-line bill has passed its third reading in Parliament tonight.
Under the bill, property-speculators who buy and sell a house within two years pay tax on their profits.
Revenue Minister Todd McClay says the bill will allow Inland Revenue to more accurately identify investors in residential property, here and overseas, and ensure they pay their fair share of tax
While the legislation passed tonight, the bright-line test will apply to properties bought from 1 October 2015.
The new tax rules will not apply to the family home, inherited property, or properties sold as part of a relationship settlement.