The format will involve 20 teams - all 10 clubs from the 2024–25 Premiership Rugby and 10 out of 12 clubs from the 2024–25 RFU Championship, with 2 Championship clubs, Cambridge and Chinnor (newly promoted) not being invited - Cambridge had finished 11th the previous season and Chinnor were newly promoted into the league.[3] This was despite 22 teams being involved in the competition in the 2023–24.
The 20 teams will be divided into 5 regional pools, each made up of 4 teams, with each side playing 6 games (3 home, 3 away). This is an improvement on the previous season, where Premiership clubs typically had more home fixtures than the Championship sides.
Teams played every other team in their pool twice, once at home and once away away. The group winners and three best placed runners up would qualify for the quarter finals.
If teams are level at any stage, tiebreakers are applied in the following order: