Spark is reassuring customers that data stored at a central Auckland building won't be affected during pending renovation work - which will include asbestos removal.
Data servers in its Airedale data centre won't be affected during the construction, it says.
Materials containing asbestos are present in the building, and while staff will be relocated while work is done, the data centre servers won't be moved.
A Spark spokeswoman said the data halls would be separated from all areas where work is happening and it wouldn't impact data centre operations.
"We don't intend to move the servers to another site - that would be very impractical for a short period of refurbishment," she said.
Level 3 of the Airedale St building is one of Spark's 17 data centres around New Zealand. Staff who work on various back office functions are also located in the upper floors of the building.
Customers who store data in the Airedale St centre have been contacted, she said.