173. A modification to a derivative comprises the reporting of the following action types: 'Modify' and 'Correct'. The timeline for reporting is the same as for the conclusion of a derivative, meaning that from the point in time when a modification is effective, it becomes reportable.

174. Counterparties should report only the modifications that have taken place, i.e. they should not report modifications that were agreed but will become effective in the future. To give an example, if the counterparties agree to amend the notional on a future date, this amendment should be reported only once the agreed date (the effective date of amendment) is reached.

175. With respect to correction, these should be reported as soon as the incorrectly reported data is identified.

176. It is not necessary to send a correction report if, following a modification of a derivative, a counterparty has introduced incorrect information only in its own internal systems but has not reported such incorrect data to the TR. In such cases that counterparty should only send the modification report containing final, correct data (i.e. does not have to send modification report with the incorrect data and then correction).