Because large-scale national clearing and settlement systems are often opened only to banks and other depository institutions, the majority of retail payments will ultimately pass through a bank generally as part of batch settlement. In order to facilitate this activity, non-bank financial institutions involved in payments, as well as unregulated Payment Sector participants, generally maintain deposit accounts with banks. These accounts can be used to safeguard customer funds (for example funds that have been deposited with a prepaid scheme) or to aggregate customer funds before disbursing them directly to customer’s account (for example when a merchant acquirer aggregates multiple payments to a merchant partner before disbursing them in a single transfer). Correspondent Banking Relationships in which the correspondent’s customers’ funds flow through an account held at the respondent financial institution are particularly high risk, because they expose the respondent institution directly to any potentially illicit activity in which the correspondent’s customers are engaged. Because banks that offer services to correspondents have limited information on these transactions, they are reliant on the correspondent to implement an effective AML/CFT program. Please see section 3.4.2 for the respective preventive measures.