Optus has agreed to offer remedies to over 8,700 of its NBN customers due to upload and download speeds that were lower than advertised.

Between 1 September 2015 and 30 June 2017, 48% of customers on the “Boost Max” plan were unable to reach the maximum promised speeds, and 21% could not reach half those speeds. Another 3% were unable to reach a quarter of the promised speeds. Customers on both the fibre to the node (FTTN) and fibre to the building (FTTB) plans were affected.

Optus has agreed to compensate affected customers in an undertaking overseen by the Australian Competition and Consumer Commission (ACCC).

“Worryingly, many affected Optus FTTN customers could not even receive the maximum speed of a lower-tier plan. This is a concerning trend we have seen throughout the industry and we are working to fix this,” said ACCC chairman Rod Sims.

The proposed compensation gives affected customers the choice to remain on their current plan without a refund, move to a lower-speed plan with a refund or cancel their contract and receive a refund.

The undertaking also requires Optus to check up on new customers within four weeks to confirm they are receiving the speeds they expect. If not, Optus will notify the consumer and provide them with options to remedy the situation.

“This undertaking is yet another step towards an industry standard of providing accurate information to consumers about the speeds they can achieve in real-world conditions, and ensuring that consumers get what they pay for,” Mr Sims said.

This is the second time in as many months that an internet service provider has agreed to compensate customers for slow speeds, with Telstra offering refunds to around 42,000 customers in November.

The ACCC stresses that, since internet speeds can be affected by the amount and quality of copper wiring from the customer’s property to the node (for FTTN) or basement (for FTTB), affected customers who choose to move to another provider may encounter the same problem.