Products such as Outlook, Azure cloud computing and Teams were affected.
There were thousands of reports of Microsoft failures across the country, according to DownDetector, a site which monitors internet outages.
Parliamentary Services said the Parliament precinct was experiencing problems, suggesting a downed server might be to blame.
It came a day after Microsoft services including Outlook and Minecraft were subject to a cyber-attack, and nearly two weeks after a botched software rollout by a third party took down millions of computers running Microsoft Windows.
The reports began shortly before 8.30am on Thursday. Around 9.45am, many users online began reporting the services were functioning again.
"We're investigating reports of access issues with Microsoft 365 services, including Exchange Online, for users in New Zealand," it said on social media.
"More information can be found under MO844647 in the admin center."
More to come...
