Waiting for an NBN technician, only for them not to show up, has proven a common frustration for Australians.

Key points: ACCC head confirms penalties for NBN Co for missed appointments "some time this year"

ACCC head confirms penalties for NBN Co for missed appointments "some time this year" NBN Co surprised by announcement given inquiry is currently underway

NBN Co surprised by announcement given inquiry is currently underway Pressure on NBN Co from government to be profitable

But NBN Co will have to end the tardiness within months or face penalties, ACCC Chairman Rod Sims has revealed.

"[The regulation] will go to people turning up when they say they'll turn up and penalties if that doesn't happen," he told Patricia Karvelas on the National Wrap, confirming the new rules would be introduced "some time this year".

Teresa Corbin, CEO of the consumer group ACCAN, said delays to installation or repairs "can result in much stress and detriment" for Australians.

"We often hear from consumers who have service faults which last for long periods of time due to missed appointments from technicians," she said.

"When outages occur people may be unable to access government services, education and employment opportunities."

The penalties have not been finalised, but figures have been proposed in industry discussions: $25 per connection for every missed appointment above an agreed acceptable level of missed appointments.

This money would not be paid to the consumer. Instead it would go to the retail company such as Telstra or Optus.

There were 82,552 missed appointments in the 2016 calendar year.

NBN financial squeeze

The ACCC launched an inquiry into NBN service standards in November, covering issues like missed appointments, and continues to receive feedback on a discussion paper.

The discussion paper considers cost implications of increased service standards and the potential for better consumer outcomes.

Tougher service standards will add more costs to NBN Co.

The ABC understands senior executives in NBN Co were surprised to hear Mr Sims appearing to pre-empt the outcome of the inquiry.

A spokesperson told the ABC that the organisation understood the inquiry was about whether regulation was "necessary".

The government intends for the NBN to return an investment for the taxpayer when it is sold following the completion of the roll-out sometime after 2020.

Malcolm Turnbull has expressed frustration that the NBN would not deliver the kind of return on investment taxpayers would expect from other projects.

NBN Co is currently working to deliver its submission to the inquiry in the coming weeks, and "assessing potential business impacts".

According to the Telecommunications Industry Ombudsman's annual report, more than 27,000 complaints had been received about the NBN and missed appointments had led to delays for small business.