Origin Energy will refund thousands of customers nationwide up to 60 dollars each per household after an Australian Competition and Consumer Commission investigation into billing practices found its "Ongoing Saver" electricity plan gave incorrect savings estimates.

The regulator confirmed customers were deceived about potential savings against standard rates according to the findings.

The total refund amount is 270,000 dollars, which equates to a significant payout in the sector.

Affected customers will be given payments automatically without submit claims shortly.