All seven defendants who entered pleas Wednesday have agreed to cooperate with prosecutors seeking convictions against other House members and staffers implicated in the probe. They have yet to be sentenced.
Among the aides who admitted breaking the law were Mike Manzo, the former chief of staff to former Democratic leader Bill DeWeese, who also has been charged.
Former state Rep. Mike Veon and three former Democratic aides are scheduled to go on trial later this month.
Deputy state attorney general James Reeder called the pleas a victory for justice and for Pennsylvania taxpayers.