Imagine logging on to do some online banking and finding out you've been made a millionaire. Well that's exactly what happened to Kieran McKeefery, 21, from Barnsley in south Yorkshire.
He found his balance had been boosted by £1,245,000.
After thinking of what to spend the cash on, he contacted his bank, NatWest, and asked them to investigate.
It turned out the transfer had come from an investment company and it was up to their bank to claim the money back.
After ten days, that's what happened, but Keiran was left with £204 interest.