Excess liquidity

 Excess liquidity is the liquidity that banks hold in excess of the aggregate needs arising from minimum reserve requirements and autonomous factors amount.

 Excess liquidity is defined as deposits at the deposit facility net of the recourse to the marginal lending facility, plus current account holdings in excess of those contributing to the minimum reserve requirements.

In normal times, when the interbank market functions properly, banks would channel liquidity to each other across the system and excess liquidity would have little or no reason to exist, because the cost opportunity of holding it would be just too high.