An ACT woman has won $50 million after purchasing a $5.55 Powerball ticket from a store at Gungahlin in Canberra's north.

The woman, who wished to remain anonymous, was contacted by a NSW Lotteries official this morning and told of the win.

"The only thing I can say at the moment is I'll be able to buy myself a house. It will be my first home," she said.

The woman said she also planned to donate money to charity.

"I moved to Australia more than 10 years ago so I want to give back," she said.

The winning ticket was purchased at Gungahlin Centre News, which has a history of selling winning tickets.

Owner Rudy Lu said last December his newsagency sold a division one winning entry worth $1 million.

"But this one is a very big one, so we're very excited about that," he said.

"It means we are a lucky store."

Powerball winner bought cheapest ticket

Mr Lu said the winning ticket was the cheapest option available.

"She just spent $5.55 to buy a six-game quick pick and she won the $50 million, so you've got to be in it to win it no matter how much you spend," he said.

Mr Lu said he had not spoken with the woman who purchased the ticket, but her win had sparked a lot of interest in the store.

"Me and my family and all my staff, they are all excited," he said.

"A lot of people have come to check in a ticket ... people from the news have come. And some friends come to say congratulations. It's really busy."