Comment by teruakohatu

What will happen is the same as when my govt. added GST (sales tax) on all imports with no de minimus exception [1], the overseas retailers will agree to add it on at checkout so their packages will sail through customs.

From a practical perspective I can’t see any other way.

Closing the “GST loophole” as they called it didn’t help New Zealand retailers, but did increase tax revenue and raise prices for consumers.

[1] There is an exception if the retailer does less than a certain dollar figure of exports in total to New Zealand.