A payment system is a set of instruments, procedures and rules for the transfer of funds among participants in the system (credit institutions or financial institutions). The system relies on an agreement between the participants in the system and the system operator, and the funds transfer is performed via an agreed upon technical infrastructure.

(Source: the CPSS report titled Core Principles for Systemically Important Payment Systems, the Bank for International Settlements, January 2001)

A central securities depository (CSD) is a system (or an institution) for holding securities, which enables securities transactions to be processed by book entry. Physical securities may be immobilised by the depository or securities may be dematerialized (so that they exist only as electronic records). In addition to holding in custody, a central depository for securities may incorporate matching, clearing and settlement functions.

A securities settlement system (SSS) is a system which allows the transfer of securities, either free of payment (free delivery or FoP), as in the case of a pledge, or against payment (delivery versus payment or DvP). Settlement of securities occurs on securities deposit accounts held with the CSD (either private CSDs or a national central bank acting as a CSD) or with the central bank (safe custody operational accounts). In the latter case, the central bank acts as the intermediate custodian of securities. The final custodian is normally a CSD. Settlement of cash occurs in an interbank funds transfer system (IFTS), through a settlement agent.

(Source: Glossary of terms used in payments and settlement systems, drafted by the Committee on Payment and Settlement Systems (CPSS) of the central banks that are G10 countries, Bank of International Settlements, Basel, March 2003, http://www.bis.org/).

In Romania there are three interbank payment systems: one for large-value payments in lei (ReGIS), one for retail payments in lei (SENT) and one for large-value payments in Euro (TARGET2-România).

There is also a central depository and securities settlement system for government securities and certificates of deposit issued by the National Bank of Romania (SaFIR) and a clearing/settlement system of securities (RoClear), that settles in REGIS.

All the afore-mentioned systems ensure the settlement via credit institutions' accounts opened in NBR.