Southend claimed their spot in League 1 for the 2015/2016 season after beating Wycombe 7-6 on penalties at Wembley Stadium.
Before the tension of penalties, Southend striker Joe Pigott had dramatically equalised for Phil Brown's men with a last grasp goal following Joe Jacobson's opener for Wycombe in the first period of extra time.
Former Bantam Will Atkinson was part of Southend's triumphant team at Wembley.
City's previous visit to Roots Hall came back in December 2012 when Phil Parkinson's side drew 2-2 against Southend just a few days after the Bantams' sensational Capital One Cup victory over Arsenal.
The final place in League 1 next season will be taken up by the loser of Sunday's League 1 Play-Off Final between Preston North End and Swindon Town.