At a high level, the requirements are:
TransUnion requires a minimum of 100 records in order to begin reporting. Data Providers should report consumer account updates once per month at the end of a billing cycle for their complete file (accounts in good standing and delinquent accounts). Notify TransUnion prior to making any changes to your reporting frequency.
For more information regarding the reporting requirements, Please contact our Client Services Department at (800) 730-0126 or email firstname.lastname@example.org