cards
PAYMENTS SIGNAL · REFERENCE CARDCard payment authorization
Maya Chen pays Demo Coffee Ltd by card. The request travels terminal to acquirer to network to issuer and back in seconds — through Cardnet, a fictional card network standing in for Visa/Mastercard-style networks. (SYNTHETIC / TRAINING ONLY)
Actors
- Maya Chen (cardholder)customer
- Demo Coffee Ltd (merchant terminal)customer
- Meridian Bank (acquirer)bank
- Cardnet (card network)infrastructure
- Bank Alfa (issuer)bank
Messages
- 0100 authorisation request (ISO 8583)
- 0110 authorisation response
The sequence
| # | Step | Route | Kind |
|---|---|---|---|
| 1 | Card presented — Maya presents her card | Maya Chen → Demo Coffee | message |
| 2 | 0100 auth req — The terminal builds and sends the authorisation request | Demo Coffee → Meridian Bank | message |
| 3 | 0100 forwarded — Meridian Bank forwards the request to Cardnet | Meridian Bank → Cardnet | message |
| 4 | Route on BIN — Cardnet routes the request to Bank Alfa | Cardnet → Bank Alfa | message |
| 5 | Issuer checks — Bank Alfa checks the card, the funds and the risk | Bank Alfa | internal |
| 6 | 0110 auth resp — Bank Alfa approves and responds | Bank Alfa → Cardnet | message |
| 7 | 0110 relayed — Cardnet relays the approval to Meridian Bank | Cardnet → Meridian Bank | message |
| 8 | Approved — The terminal shows approved | Meridian Bank → Demo Coffee | message |
| 9 | Auth hold — Bank Alfa places an authorisation hold | Bank Alfa | posting |
Exception rails
| Rail | Trigger | Where the money ends up | Next action |
|---|---|---|---|
| Decline: insufficient funds | Maya's available balance cannot cover EUR 42.50 when Bank Alfa runs its checks. | Untouched — no hold was placed and no money moved. · None. A declined authorisation never reaches clearing or settlement. | Bank Alfa — Maya pays with another card or method; Demo Coffee simply retries the sale. |
| Stand-in: issuer unreachable | Cardnet cannot reach Bank Alfa — the issuer's host or its network link is down. | Held against Maya's account only after Bank Alfa processes the advice. · Not yet — clearing and settlement follow later and honour the stand-in approval. | Cardnet — Bank Alfa reconciles stand-in advices against its records once its systems return. |