Wellington Electricity is apologising for a breakdown in communication when power was cut to residents and businesses in the central city for hours on Sunday.
Dozens of shops in the lower Cuba St area were forced to send employees home when the electricity was turned off for maintenance about 8.30am.
Some affected people said they had no notification that any maintenance was due, while others had been told it would not affect them.
Wellington Electricity, Trustpower and Genesis are now in dispute about who's responsible for the apparent breakdown in communication.
Wellington Electricity chief executive Greg Skelton told Radio New Zealand's Morning Report programme on Monday the job had been planned for a while and apologised for the fact it appeared not to have been properly notified.
The Wellington City Council wants answers. Council spokesperson Richard MacLean says it is not clear why some people were not told about the maintenance.
"We share the concerns of especially the retailers in the area. They should've been given adequate warning, and in most cases they weren't. But the point is, it's actually a complicated situation in terms of who is actually responsible for notifying the consumers in the area."