"The issue is that under the current system, it is effectively customs officers that are the ones collecting that tax and if that threshold is lowered the cost of staff and the process would be more than the tax collected - which is not a workable system."
Bullot said the ideal collection method being looked at was for GST to be charged at the source, meaning retailers would have to register for GST in the country they were selling to, with the extra GST cost but no extra effort required for customers.
"It makes sense for them to impose GST on imports coming into Australia but trying to do it at source rather than the border," Bullot said. "That is the ultimate goal and I think maybe what will happen is you'll get the situation where you have the rule, we know it won't be enforced that much but we'll make sure we pick up the big players."
Read also:
• Online GST jump looms for NZ shoppers
• What it's like to work at Amazon - 'Nearly everyone I worked with I saw cry at their desk'
• Amazon debuts free shipping on small goods
Lowering the GST threshold would bring New Zealand into line with the rest of the OECD, with most countries implementing a much lower level. Canada has a threshold of $20, Britain at £15 and the United States has no threshold at all, with all imported parcels subject to tax.
Prime Minister John Key has already said New Zealand would lower its threshold, although it had not been decided what that lower limit would be yet. A proposed new $20 limit in Australia would be put to treasurers there when they next met on August 21, and Key has indicated New Zealand was likely to follow Australia's lead.