Telstra appears to be suffering yet another mobile phone outage with customers reporting an inability to make phone calls.

A spokesman for Telstra said it was receiving reports of problems making calls to and from fixed-line and mobile phone services.

This came after social media began lighting up on Tuesday morning with angry customers getting patchy services.

"We've received reports from some customers facing difficulties making voice calls on our fixed and mobile networks," he said. "We're investigating as a priority."

If the outage is confirmed this would the fourth mobile outage to hit Telstra's once-sterling reputation in two months.

Telstra's suffered a national outage affecting around 8 million services last week and is set to compensate with a free data day on April 3.

That also prompted an apology from chief executive Andrew Penn.

Telstra relies on its reputation for having the best networks to justify charging its customers a premium price.

Customers took to social media to complain about the latest outage.