You only need a license if it's a acu club, amca clubs don't require licenses, I ride in twinshock trials under amca, join club, turn up, pay and enter and away you go, but I will be joining north lancs club this year (acu club) so will be getting license etc, once you have acu license you're covered to ride in any acu club trial but most clubs have open or closed trials. Open is any acu member and closed is club members only, hope that helps.... It's worth joining as many clubs as you can, subs are usually only a fiver