Audits carried out by Customs have resulted in $48 million being collected for the Crown in just over 18 months.
Customs Minister Maurice Williamson said Customs' trade assurance arm works to verify that import and export entry data is accurate, and to ensure correct revenue is collected.
Revenue includes duty and GST paid on imported goods, together with excise and excise equivalent duty which is payable on tobacco products, fuel and alcohol products.
"In the financial year to June 2012 audits resulted in $31 million in additional revenue being collected. This financial year, trade assurance has accounted for an additional $17 million.
"These amounts are well above the targeted figure of $15 million a year and shows systems Customs has in place are working well," Mr Williamson said.