Gas supply was earlier restored to essential services including hospitals, most of the dairy companies, small businesses and small users of gas, but major users have until now been unable to reconnect.
Vector said restoring supply needed to be done in a staged and managed way to maintain the integrity of the system - a process that required close and careful monitoring.
Commercial customers should not use gas until advised by their retailer.
Vector chief executive Simon Mackenzie said he was pleased the Maui pipeline was back in service and that the last remaining customers would be brought back online.
The Vector pipeline, which has continued to supply gas to Auckland, has now been reconfigured to normal operation.
Acting Energy and Resources Minister Hekia Parata thanked the sector for their collaborative efforts since the outage began.
"And, of course, the quarter of a million Kiwi homes that reduced their use to make it possible to spread the capacity of the second Vector pipeline that flowed throughout," she said.
"It has been this collective effort that has seen the pipeline repaired and the outage managed in such a timely manner."