Adam Birchall, Michael Leary, Nicky Nicolau and Ran Kadoch have all been told they have no future at the club, joining Max Porter in departing.
"Releasing players is not a pleasant job but the sole aim is to take Barnet FC forward," Barnet boss Ian Hendon told his club's official website. "Perhaps it is time for a change for both club and players."
Veteran Paul Furlong has also been offered a one-year deal. He has returned to Southend after his loan spell at Underhill.