Villa were given dispensation to complete a £5million deal for Dunne as negotiations over his departure from Manchester City rumbled on past the 5pm deadline.
Under Premier League rules, Villa were able to continue trying to sign Dunne provided they started formal proceedings to tie up the deal by the 5pm cut-off.
Dunne had passed a medical and settled personal terms with Villa after the clubs agreed a fee before the weekend. But the Ireland defender wanted compensation for giving up a testimonial at City next summer.
He did not ask to leave City and still had three years left on his £55,000-a-week contract. It is believed the initial offer made by City fell well short of what Dunne felt was a reasonable figure.
A source close to the player told the Daily Mail: "Richard believes the initial offer he received from Manchester City was not befitting someone who had given nine years' service."