The Bantams were thrown out of the competition by the Football Association last week because they did not receive written permission in time to play Newcastle loanee Curtis Good in the second-round meeting with Brentford on November 30, which finished 1-1,
But following an appeal, Bradford say the FA has decided to fine the club and allow them back into the competition.
It means Bradford, who reached the semi-finals of the Capital One Cup after following Tuesday night's thrilling penalty shoot-out win over Arsenal, will now travel to Brentford for the FA Cup replay next Tuesday, with the winners to face Southend in the third round.
A Bradford statement read: "Bradford City FC can confirm that today director of operations David Baldwin attended an appeal hearing with Ben Jones, Partner at Petherbridge Bassra solicitors and Mr Simon Csoka QC of Carmelite Chambers.
"The appeal was heard before the FA Appeal committee at Wembley Stadium in relation to the matter of the club's expulsion from this season's FA Cup with Budweiser competition.
"We can confirm that on appeal the club has now been reinstated back into the FA Cup competition and has been fined for its actions.
"We deeply regret our breach of the rules and are currently reviewing our procedures to ensure no repeat of this situation.
"Therefore the original replay of the club's FA Cup second-round tie at Brentford FC, scheduled for Tuesday, December 18 2012, will now take place at the Bees' Griffin Park stadium."
- Sports & Recreation