Telstra has been ordered by the Federal Court to pay a $18 million penalty for breaching the Australian Consumer Law after moving nearly 9,000 Belong customers to lower-speed broadband plans without proper notice.

In October and November 2020, Telstra migrated 8,897 Belong NBN customers from plans with a maximum upload speed of 40Mbps to a plan capped at 20Mbps, while maintaining the same 100Mbps download speed. Customers were not informed of the change at the time.

“Telstra’s failure to inform customers that their broadband service had been altered denied them the opportunity to decide whether the changed service was suitable for their needs,” ACCC Commissioner Anna Brakey said.

Telstra will also compensate affected customers with $15 per month they were on the reduced upload speed plan, amounting to more than $2.3 million in total.

Some payments were made before court proceedings; others will be processed under a court-enforceable undertaking, with affected customers contacted by Belong.

The court also ordered Telstra to pay a contribution to the ACCC’s costs. Telstra cooperated with the ACCC during proceedings and made joint submissions regarding orders and penalties.

Belong, launched by Telstra in 2013, operates semi-independently, offering low-cost mobile and internet services.

The downgrade followed changes to wholesale speed tiers by NBN Co, which offered the lower-speed tier at $7 less per month. Telstra did not pass this price reduction to customers.

This latest penalty adds to a series of regulatory actions against Telstra.

In March, Telstra paid a $626,000 penalty for spam breaches; in December 2024, it was fined $3 million for emergency call disruptions; and in July 2024, Telstra disconnected from the emergency call relay service for nearly 13 hours.

Telstra reported a 6.5% net profit increase to $1.03 billion for the six months to 31 December 2025, despite these setbacks.

The fine comes at a difficult time for rival telco Optus, which has faced a string of high-profile regulatory setbacks including a record $100 million fine for unconscionable sales practices and a major Triple Zero outage.