Spark New Zealand has reported that 3G usage on its network is down by 70 percent since June.

Significantly, that was when Spark confirmed a hard date for its 3G shutdown, which is set for March 31, 2026.

In an announcement today (January 27), Spark revealed that 3G data usage is down 50 percent and accounts for only 0.25 percent of Spark's total network data traffic, while 3G voice usage is down by 70 percent since June.

During the same period, Spark reports that 4G data usage has grown by 17 percent and 5G data usage by 37 percent.

“Building a network requires constant futureproofing. It’s been almost 17 years since we first launched our 3G network, and now it’s time to say goodbye," said Michael Molony, general manager of network evolution at Spark.

"Shutting down a network takes years of planning, from upgrading sites and reallocating spectrum to testing critical services and working closely with our customers to ensure a smooth transition.”

Molony did urge the remaining customers still using 3G devices to upgrade ahead of the switch-off date.

Spark said it would shut down the network by the end of 2025 back in 2023, but extended its shutdown to this year to give customers more time.

The company, which first launched its 3G network in 2009, revealed that less than two percent of its entire network data traffic runs over 3G, while 3G voice calls have declined by 85 percent since 2019.

As part of its 3G retirement, Spark has upgraded its 4G and 5G networks. Since 2023, the carrier said it has built more than 70 new 4G mobile sites and upgraded more than 600 others.

Domestic rival 2degrees started its 3G switch-off last month, while One NZ also started its 3G shutdown this month ahead of a March 31, 2026, nationwide retirement.