Inland Revenue has for the third year set out its priorities to make sure taxpayers comply with the rules, and says it will again be closely monitoring the cash-generating parts of the economy.
The department says it has exceeded expectations on cracking down on the hidden economy, pulling in $118.5 million by the end of April.
The Commissioner of Inland Revenue, Bob Russell, says the department will continue this work, including looking at businesses that have a mix of cash and other sales such as the hospitality sector.
It will look at other areas of the the economy where there is an opportunity to suppress income, such as contracting, trades and motor repair businesses.
Mr Russell says IRD will also ensure firms are correctly applying the rules when offsetting profits against past losses.