The Bantams, who defeated Arsenal in the Capital One Cup on Tuesday, were expelled from the FA Cup for fielding ineligible Australian Curtis Good in the second round
The decision means Bradford remain undefeated in every cup game they have faced this season, following their dramatic penalty shootout victory over Arsenal in Tuesday's Capital One Cup and progress to the northern area semi-finals of the Johnstone's Paint Trophy.
The FA confirmed on their website that the original ruling on December 7 to expel the club from the FA Cup because of an administrative error over the registration of on-loan Newcastle defender Curtis Good, was overturned due to a number of factors.
The governing body accepted the "genuine error and recognised that corrective action was attempted as soon as the omission was discovered and that no attempt to deceive was made".
They also asserted that the League 2 club reported the error prior to the original game against Brentford as well as confirming that former Melbourne Heart man Good was eligible for the fixture aside from the administrative oversight.
On this basis, Bradford have been reinstated but forced to pay a fine of £1000 for the mistake. The replay of the second-round tie against Brentford will take place at Griffin Park on December 18.
Good, 19, has made two appearances for City since joining on a short-term loan in November, and was among the substitutes for Tuesday's win over Arsenal.
Fellow Australian James Meredith played 90 minutes against the Gunners.