In order for banks from different countries and with different business models to have sufficient collateral to access liquidity, the Eurosystem accepts a very wide range of marketable and non-marketable assets, which must fulfil certain eligibility criteria.
For marketable assets, i.e. for marketable debt securities, the ECB publishes the list of eligible marketable assets on its website, common to the entire Eurosystem.
The list of eligible non-marketable assets is not published. The assessment of the eligibility of non-marketable assets is carried out by the NCBs.
The correspondent central banking model (CCBM)
The CCBM enables all Eurosystem's counterparties to access eligible assets from the entire euro area.
For more on the CCBM see ECB website