The Sydney lawyer first discovered the mystery millions in her account on October 25 and notified the bank, however it's still in her bank.
the young woman shared the photo of the mistaken money to Facebook, teasingly asking 'Do I skip the country?'
The post continued, 'When NAB accidentally pays out your entire mortgage and gives you an extra $24.5mil to redraw.'
Feeling 'quite great' when she first saw the large sum of money, Ms Wainwright told Fairfax she contacted NAB about the error but two days later, nothing had been done.
The lawyer said 'both banks have messed up' because NAB first requested $25.1 million from her bank, St George Bank, who then transferred the substantial figure, heavily overdrawing Ms Wainwright's account.
Not tempted to spend the money, like other people have been caught doing in the past, Ms Wainwright said it 'wouldn't play out that well' if she 'played dumb' about the excessive figure in her account.
NAB have claimed they are looking into the reported issue.
This article originally appeared on New Idea.