The borders of both countries, along with Canada, have effectively closed to inbound and outbound travel along with a growing list of other countries throughout Europe and Asia.
NZ Post says it is closely monitoring the situation in response to Covid-19 and delays its aircraft partners are facing. It could not confirm which or if any of its airline partners had been affected by the outbreak, though it was anticipating this.
"We cannot comment on specific partners for commercial reasons, but as has been widely reported in the media, most airlines have or will experience issues with the changes announced. The extent is not clear yet as airlines work through scheduling changes," a NZ spokeswoman told the Herald.
"We are working with our partners to determine the impacts to NZ Post and we will enact our continuity planning as appropriate, which can include the use of alternative carriers.
"This is a rapidly changing and fast-moving situation, so we expect we may be able to share more details on any delays in due course."
The spokeswoman emphasised there were no delays in delivering parcels, once they had arrived in New Zealand.
"Certainly online shopping domestically won't be impacted as long as stock is available, but if you're ordering online from overseas you may well find that there are delays in the ability of online e-tailers to get that stock to you," Greg Harford, chief executive of Retail NZ, told the Herald.
"That's because the number of planes flying to New Zealand is collapsing. There could well be significant shortages in freight arriving and delays."
Harford said it was often hard to know where products brought over the internet was shipped for and therefore to plan for any major delays.
"If you are shopping online from overseas then you need to start thinking about delays."
DHL, another major delivery partner for parcels to and within New Zealand, has been contacted for comment.
New Zealand has experienced a drop-off in discretionary spending over the past few weeks as news of Covid-19 hits home. The grocery sector has seen a lift in sales.
Retail NZ says sales in stores are down 60 per cent as a direct result of the outbreak, while sales online are down about 10 per cent.