The Customs Service is training postal staff to screen incoming international mail for items liable for GST and duties, saying the move will free up its officers to spend more time detecting contraband.
Kiwis' love of retail websites such as amazon.com means increasing amounts of goods bought online are coming across the border.
Freight operator DHL Express said last month that it had seen a 30 per cent rise in its inbound deliveries during the first quarter this year - primarily as a result of online shopping.
Most items bought on overseas websites can be imported free of charges if they are valued at less than $400, including freight and insurance costs.
However, the threshold is lower for goods to which duties apply, such as footwear and apparel.