Eight providers — Telstra, Optus, TPG, iiNet, Internode, Dodo, iPrimus and Commander — have all admitted that they falsely represented the speeds that could be experienced by NBN users who were on fibre-to-the-node or fibre-to-the-building connections.

These providers advertised NBN plans with maximum speeds of 100Mbps down and 40Mbps up, when it was impossible to attain such speeds on FttN and FttB connections.

The ACCC said since November 2017, it had accepted undertakings from these providers that they would contact more than 142,000 affected customers and offer them a change of plan, or an end to the contract and a refund.

“A large proportion, two in three affected consumers, have not responded to the letter or email from their RSP. They may be eligible for refunds, some in the hundreds of dollars,” ACCC acting chair Mick Keogh said.

“The ACCC is urging NBN customers to contact their NBN retailer if they have received a letter or email offer of a remedy, or think they might be entitled to a remedy.”

The watchdog said customers who had recently signed up to a new NBN plan may also be eligible for a refund where the RSP advertises maximum connection speeds with the plan.

RSPs are under obligation to check their speeds within four weeks and, if the speeds are below those advertised, remedial actions must be offered.

“Our message to RSPs is that if you advertise a particular connection speed and customers cannot experience that speed, you risk breaching the Australian Consumer Law,” Keogh added.

“We expect RSPs to provide consumers with accurate information up front about the Internet speeds they can expect to experience, and then deliver on those promises.”