They began as a pop punk trio, with Rich's brother Neil Mandell on bass.

[2] After releasing an EP and a split 7-inch on Don't Ask Records in 2014, and relocating to London, the band signed to Alcopop!

It was recorded with Matthew "MJ" Johnson of Hookworms at his studio Suburban Home.

[6] Happy Accidents announced in May 2021 that they would cease to play and tour as a live band, but that they might still record and release new material.

[8] In July 2024 Happy Accidents announced the release of their fourth album, Edit Undo, on 27 September 2024.