Spark New Zealand (ASX:SPK, NZE:SPK) said 3G voice usage declined 70% and 3G data usage fell 50% in New Zealand in January after it declared the March 31 shutdown date for the service in June 2025, according to a Tuesday statement.

Meanwhile, 4G data usage climbed 17% and 5G data usage jumped 37% over the same period.

It sent over 2 million notifications via emails, texts, letters, pre-call announcements, and bill inserts offering guidance on the change and how to transition to 4G and 5G networks, per the statement.