Internet ADSL and NBN services appear to down in some areas of NSW, Victoria, Queensland, WA, SA and Tasmania.

Irritated Telstra customers have taken to Twitter, and the hashtag #telstraoutage is trending.

The website Aussie Outages has received hundreds of outage reports, since about 11am Saturday.

A Telstra spokesperson confirmed the outage on Saturday afternoon.

"We are aware of an issue impacting some of our ADSL and NBN customers," the spokesperson said.

"We are working as quickly as possible to identify the problem and a solution, and we apologise for any inconvenience."

There were several other outages reported earlier in the year, in February Telstra's chief operations officer Kate McKenzie said another widespread outage was caused by "human error".​