Our Treaurer isoff with the fairies, page-44

In this way, the Reserve Bank is able to directly influence the cost of overnight lending between banks.
But overnight borrowing only makes up a tiny amount of banks' total borrowing.
More than half of banks' funding these days comes from depositors. These are people who put money in the bank and expect, in return, to be paid interest.
The bulk of the remaining funding comes from borrowing money from other banks and investors over longer periods than overnight. Roughly half of this "wholesale funding" comes from domestic sources and half from offshore