585. Expanding the use of ISO 20022, ESMA proposed in the Consultation Paper that standardised response messages compliant with ISO 20022 are sent by the TRs to the RSEs and, where relevant, reporting counterparties or ERRs within one hour after the submission of data to the TR. The response message should include necessary details about the acceptance or rejection of submitted reports and the errors found. The TR should also enable the reporting counterparties or ERRs to access the data reported on their behalf.

586. ESMA proposed four rejection categories: schema, permission, logical and business. Authentication failures will not be included in the rejection response because those cannot be uniquely attributable to derivative reporting or specific derivative. TRs should be able reject the derivatives at UTI level and specify the errors.

587. Most respondents to the consultation generally agreed with the proposal or did not raise any objections. One respondent opposed to mandating ISO20022 message format. One respondent suggested that one-hour response requirement should allow for exceptions in special circumstances. Some respondents suggested sending the immediate rejection responses only to the RSEs, while the counterparties, ERRs and other relevant entities would be provided with end-of-day rejection responses only. One respondent proposed that RSEs instead of TRs should be mandated to provide the rejection responses to the reporting counterparties and ERRs.