Barnet remain rooted to the bottom of the League Two table after being heavily beaten at Bradford.
After a tight first half, the home side took the lead when James Hanson headed in a deflected Gary Jones free-kick.
The Bantams made it two when Alan Connell slotted home from close range after Bees goalkeeper Graham Stack failed to hold a Kyel Reid cross.
Defender Andrew Davies then headed in another Jones free-kick from inside the six-yard box for Bradford's third.
VIEW FROM THE DRESSING ROOM
Barnet manager Mark Robson told BBC London 94.9:
"We switched off in the second half. I thought we defended superbly in the first half. We limited Bradford's chances.
"Within two minutes of the second half we did the complete opposite and we ended up shooting ourselves in the foot, so you can imagine my frustration.
"I am frustrated, the players are frustrated with themselves but ultimately a game is 90 minutes, and at the moment we're not producing 90 minutes.
"As a team, we have to be strong, stick together and cut out our mistakes."