According to Australian media, it's too early to say, but Optus CEO Kelly Bayer Rosmarin apologised to customers and thought that the company might compensate for the shutdown.

"Now that the network is restored we will have a look at ways we can thank our customers for their patience and reward them for their loyalty," she told 9News.

Communications Minister Michelle Rowland indicated that impacted consumers may be compensated, but not just yet.

"In relation to customers who have been affected and what they recourse may be, I note the comments by the Telecommunications Industry Ombudsman (TIO) that at this time it probably too early to be discussing or giving definitive views about compensation or other consumer rights," she said.

However, she advised customers need to keep track how the outage affected them.

The Australian and Communications and Media Authority (ACMA) recommended that customers affected by the outage should file a complaint with their telco.

According to the regulator, consumers may be entitled to a refund or compensation depending on the contract.

But if the outage is short and minor, it is unlikely that consumers will get any refund.

"Some contracts allow you to apply for a refund or rebate when you can't use a service because of an outage. This is usually only for major outages that you did not cause."

"Sometimes a telco will offer compensation for the loss of service, even if they don't have to."

The Telecommunications Industry Ombudsman (TIO) said customers unhappy with Optus' response can file a complaint.

"If you have not contacted Optus, or you have been unable to contact them, we can forward your complaint to Optus on your behalf," it said after the shortage began.

"We can help you with refunds for the time you have been unable to use your service, compensation claims and disputes about your contract."

Actions taken
Rowland also said the government will undertake a post-incident telecommunications review.

"While we welcome that Optus services were restored over the course of the day, it is critical the Government conducts a process to identify lessons to be learned from yesterday’s outage," she said in a statement.

"I will task my Department with developing the terms of reference for a post-incident review. Further announcements around the terms of reference and next steps will be made in due course."

Optus was hit by an outage yesterday at 4am. At 5:30pm AEDT, Optus was able to restore its services, almost 12 hours after the shutdown.

"Services have now been restored, and customers should now be able to be back online," Optus said.