| CB | Central bank |
| CBT | Computer-Based Terminal |
| CCBM | Correspondent Central Banking Model |
| CCBM2 | Collateral Central Bank Management |
| CCITT | International Consultative Committee for Telegraphy and Telephony |
| CCP | Central Counter Party |
| CET | Central European Time |
| CHAPS | Clearing House Automated Payment System |
| CI | Credit Institution |
| CIT | Customer Implementation Team |
| CLS | Continuous Linked Settlement |
| CM | Contingency Module |
| COGEPS | Contact Group on Euro Payments Strategy: (Kontaktgruppe der EZB zum Austausch zwischen Kommerzbanken und dem ESZB) |
| CPSS (CPSIPS) | Core Principles for Systemically Important Payment Systems |
| CRSS | Customer Related Service Systems |
| CS | Clearing Service(s) |
| CS.A | Clearing Service Austria |
| CS.I | Clearing Service International |
| CSD | Central Securities Depository (Zentralverwahrer für Wertpapiere) |
| CUG | Closed User Group |
| CUSIP | Committee for Uniform Securities Identification Procedures |