Vodafone customers have been without internet since 3pm today.
A spokeswoman for the telecommunications giant said customers were experiencing a loss of internet, which included issues trying to authenticate connections and an inability to browse.
Customers complained of internet outages from 3pm, that were still occurring at 10pm.
Vodafone did not know the extent of the problem, or what had caused it but said engineers were working to remedy the situation.
Customers were notified via a post on the company's website, a pre-recorded phone message on its phone line and were interacting with customer service staff on Twitter.
"Our engineers are working to restore this issue and hope to have this restored as soon as possible. We apologise for any inconvenience this may cause," read the website post.
A Northland businessman, who did not want to be named, said he lost his broadband connection at 3pm, and it was still not restored by 9.30pm last night.
"I am trying to run a business and am negotiating contracts with China, I have no idea if any of the payments have gone through because I get online or anything.
"It's absolutely hopeless, they told it would be fixed by 6pm but it wasn't."
