UMS Monitoring Explanatory notes

ELEXON monitors the issue of erroneous values of Unmetered Supplies in the Non Half Hourly (NHH) market. The monitoring involves comparing UMS data from Unmetered Supplies Operators (UMSOs) and Non Half Hourly Data Aggregators (NHHDAs) on a particular Settlement Date following the SF run. The monitoring takes place quarterly and the dates used can be found in the UMS Monitoring Timetable.