An Australian couple said a breakdown in communication led to their winning a lottery jackpot of more than $700,000.

The Albany, Western Australia, couple said they normally only buy one ticket for the Lotterywest Saturday Lotto drawing, but a breakdown in communication led them each to buy a ticket on the same day.

"I discovered my partner had also bought a Saturday Lotto ticket, so I thought I better go check it," the wife said.

She said she went to Plaza Lotteries in Albany to check the ticket, and while she was there she decided to buy a Wednesday Lotto ticket, which she normally would not have done.

"I decided I might as well buy a Wednesday Lotto ticket while I was there," she said. "I don't usually play Wednesday Lotto."

The Wednesday Lotto ticket earned the couple a $717,500 jackpot.