Right, I suspect that the difference is that there never were any charges per transaction to the merchant in NZ. I've never seen a shop that had a minimum size for an EFTPOS transaction here.
On the other hand there are a lot of shops that either have a minimum transaction size, or a surcharge, on Credit Card transactions.
On the other hand there are a lot of shops that either have a minimum transaction size, or a surcharge, on Credit Card transactions.