Each period for which minimum reserves must be maintained starts on the settlement day of the main refinancing operation (MRO) following the first meeting of the month of the ECB Governing Council and ends one day before the next maintenance period begins, irrespective of whether these days are working days, Sundays or public holidays. In 2014, the ECB Governing Council decided that starting from 2015, monetary policy meetings would take place only eight times a year instead of every month. For this reason, the maintenance periods were extended to five to eight weeks, resulting in eight maintenance periods per year since 2015. The reserve maintenance periods for the following year are published at least three months before the end of each year.
Banks must fulfill the minimum reserve requirement on average over the length of the maintenance period. A bank fulfills its minimum reserve requirement if the average end-of-day balance on its reserve accounts over the maintenance period is equivalent to its reserve requirement.
The timeline below illustrates the key dates of each maintenance period.
Banks that cooperate closely with each other may hold their minimum reserves with an intermediary. In Austria, banks that are part of Sparkassen, Volksbanken or Raiffeisen networks maintain their minimum reserves with their relevant central institution as their intermediary. The intermediary, in turn, must hold these banks’ indirectly maintained reserves together with its own minimum reserves with the OeNB.