"I was horrified to be told we were Morningside," Dearlove said.
"We paid a premium to be in Western Springs, and we chose this suburb because it has dual school zones."
Dearlove and husband David wanted the option of Mt Albert Grammar and Western Springs College for their sons Riley, 4, and Mason, 2. Now they are worried their Western Springs property might not be in the Western Springs zone.
But they were concerned about more than property prices and school zones.
"It is where we live, it has been a suburb from the day dot," said Dearlove. "You can't just wipe it off the map."
The suburb data - compiled to direct emergency services to 111 calls - is sent to about 40 organisations, including NZ Post and Quotable Value.
The NZ Fire Service confirmed streets in Western Springs, Mt Albert and Sandringham were now classified as Morningside. "Morningside had previously not existed as a suburb.
"It was a locality but it was not a suburb," a spokesman said.
"We identified businesses which defined themselves as Morningside and, based on that, we created a Morningside area late last year.
This change has not removed Western Springs, it has decreased the extent of Western Springs."
NZ Post representative Jaimee Burke said the company was involved in compiling the suburb data, but the Fire Service was in charge of the process.
Jonno Ingerson from Quotable Value said he was "as surprised as anyone" by the suburb change, but accepted the Fire Service localities as official definitions for suburbs.
"It isn't often that suburbs are absorbed like this but it does happen every now and then."
Local Ray White real estate agent Ruth Hawes echoed the concerns of residents and said the agency used information from the council.
"Suburbs should not have to change all the time, surely that makes it more confusing," she said.
"This needs to be managed by an organisation that has an understanding of rates and property values."
