(37)In order to identify the relevant classes of OTC derivative contracts that should be subject to the clearing obligation, the thresholds and systemically relevant non-financial counterparties, reliable data is needed. Therefore, for regulatory purposes, it is important that a uniform derivatives data reporting requirement is established at Union level. Moreover, a retrospective reporting obligation is needed, to the largest possible extent, for both financial counterparties and non-financial counterparties, in order to provide comparative data, including to ESMA and the relevant competent authorities.