The deal has been much delayed. But industry insiders say that by the end of the year fans using iTunes will be able to buy songs from albums such as Help! and Sergeant Pepper's Lonely Hearts Club Band.
Although the Beatles last recorded together almost 40 years ago, the deal will provide huge rewards - estimated at £200million - to Sir Paul, Ringo Starr and the families of John Lennon and George Harrison.
As a result of various deals done in the past, EMI, Sony and Michael Jackson own recording or publishing rights to Beatles' songs so will get some of the cash. It is not clear what portion will go to 65-year-old Sir Paul.
Ironically, according to the Dail Mail, it's possible that Mills may up her demands for financial compensation, somewhat of a pyrrhic result.