When reviewing home loan applications, Citibank uses the credit scores from all three major credit bureaus: Equifax, Experian and TransUnion. Citibank pulls data from Equifax monthly to update its cardholders' FICO scores.
Citibank does not openly disclose which credit bureau agency it pulls credit reports from, although it is known that the bank usually pulls credit reports from Equifax or Experian. However, the particular credit bureau used typically varies depending on the applicant's state of residence and the specific credit card or account that is being applied for.
Citibank reports account payment and other credit data to all three bureaus on a monthly basis.