[1] The premise of this box set was to compile only Beatles material which was released or prepared for release with a dedicated mono mix (the set excludes later material mixed and released only in stereo, and material whose mono version was simply created as an equal mix of the two channels of the stereo version, e.g. 1969's Yellow Submarine album).

As a result, the track listing for Mono Masters differs from Past Masters on the second half of disc two, omitting some later songs that never had a mono mix ("The Ballad of John and Yoko", "Old Brown Shoe" and "Let It Be"), and adding several songs released on stereo-only albums that had unreleased mono mixes.

Tracks 9–12 and 15 of disc two were prepared in March 1969 for release as a 7" mono Yellow Submarine EP, two months after the release of the similarly titled soundtrack album, but the project was scrapped, although the EP was mastered.

"Get Back" (with B-side "Don't Let Me Down") was the final Beatles single mixed for mono format.

This compilation was released individually as a triple vinyl LP set on 9 September 2014 in Europe and the following day in North America on the same day that The Beatles in Mono box set was released in vinyl LP format.