As part of the shift, Telstra is also introducing no excess data charges across all of its plans and moving to a no lock-in model, in which consumers can switch between Telstra plans at any time.

But consumers will still be able to be caught out while travelling overseas.

"Travel packs are an addition, it's not built in. When a customer goes overseas and they roam on an international network, that operator charges Telstra," Mr Penn said.

The comments come as the ABC revealed on Tuesday at the Australian Competition and Consumer Commission were looking into whether Telstra had breached consumer law over its sales practices to vulnerable Indigenous Australians.

It was reported that Telstra had been selling customers on Centrelink contracts costing up to $250 a month, while aggressive debt collection tactics had resulted in vulnerable Australians thinking they would go to jail over the debts.

Telstra did not respond to the allegations prior to publication.

Its new products that do not have excess data charges will stop customers from racking up excessive bills.

"One of the critically important things we've done is remove excess data charges on both fixed and mobile plans," Mr Penn said.

"The new mobile plans start at $50, then $60, $80 and $100 and they all have peace of mind data.

While Telstra's core plans have been cut to 20, customers will be able to customise their add-ons, choosing things like which additional services they want included in their plans.

Mr Penn has previously labelled its T22 strategy as the most profound in Telstra's history.

As part of the make-or-break transformation, Telstra will have a substantially reduced workforce, with thousands of jobs being axed and a management structure aimed at having less bureaucracy.

It is also investing more in technology and splitting off Telstra's infrastructure assets into a standalone entity in the firm called InfraCo.

As part of the overhaul 8000 roles will be lost, while 1500 new ones will be created.

In the last three years Telstra has spent about $3 billion updating its IT systems and building its 5G network.

While 5G is expected to herald a new era for telecommunications with faster speeds and lower latency, but tests by phone comparison website WhistleOut indicated the speeds and latency at this stage were similar.

Despite this, Mr Penn was confident its network would deliver speeds up to 10 times faster than the 4G network.

"We are on the first generation of 5G, but at our Gold Coast lab we were getting 3 gigbit per second speeds," he said.

"There can be a technical reason for why people can't simulate the tests.

"I was in Toowomba last week with 5G coverage and sitting there with 5G and 5G running simultaneous tests and getting three times the speed."