Card Network Processing
Overview
Card networks (Visa, Mastercard, American Express, Discover) facilitate electronic payments using debit and credit cards. Unlike ACH or Fedwire — which are bank-to-bank fund transfer systems — card networks operate a four-party model involving cardholders, issuers, merchants, and acquirers, connected by the card network's infrastructure.
Card transactions are not settled in real time. Authorization occurs instantly at point of sale; clearing and settlement happen through a batch process typically on T+1 or T+2 schedule.
The Four-Party Model
| Party | Role | Example |
|---|---|---|
| Cardholder | Consumer or business that holds and uses the payment card | Individual making a retail purchase or online payment |
| Issuer | The bank that issued the cardholder's card. Authorizes transactions and is responsible for the cardholder relationship. | Chase, Bank of America, Wells Fargo (as card issuers) |
| Card Network | Operates the messaging and rules infrastructure between issuers and acquirers. Does not hold funds. | Visa, Mastercard, American Express, Discover |
| Acquirer | The bank or payment processor that processes card transactions on behalf of the merchant. Receives settlement funds and pays the merchant. | Stripe, Square, JPMorgan Chase Merchant Services |
| Merchant | Accepts card payment from the cardholder. Funded by the acquirer net of fees. | Retail store, e-commerce website, service provider |
Card Transaction Lifecycle
Phase 1: Authorization
Presents Card
Terminal
Processor
Network
Authorizes
At point of sale, the authorization message (ISO 8583 format) travels in real time from the merchant terminal through the acquirer to the card network, which routes it to the issuer. The issuer checks: available credit/funds, card status (not blocked/expired), fraud rules, and OFAC screening. The issuer responds with Approve or Decline in seconds. An authorization holds funds — it does not move them.
Phase 2: Clearing
At end of day, the merchant batches all authorized transactions and submits them to the acquirer for clearing. The acquirer sends clearing files to the card network. The network routes clearing items to the appropriate issuers. Clearing data includes the final transaction amounts (which may differ from the authorized amount — e.g., restaurant tips added post-authorization).
Phase 3: Settlement
The card network calculates net positions between all issuers and acquirers in its network. Settlement occurs through the card network's settlement bank (typically Fedwire or other Fed mechanism). The acquirer receives net funds (less interchange fees) and then remits payment to the merchant (less acquirer fees).
| Phase | Timing | Who Initiates | Financial Impact |
|---|---|---|---|
| Authorization | Real-time (seconds) | Merchant terminal | Funds held (not moved) |
| Clearing | End of business day (batch) | Merchant → Acquirer | Final amounts confirmed |
| Settlement | T+1 to T+2 | Card network → Issuers/Acquirers | Funds moved between banks |
| Merchant funding | T+1 to T+3 | Acquirer → Merchant | Merchant receives net proceeds |
Settlement at the Bank Level
For financial institutions that are card issuers, the daily card settlement cycle generates significant fund movements through the institution's accounts. Key operations considerations:
- Issuer settlement: The card network debits the issuer's settlement account daily for net card purchases by the bank's cardholders. The issuer recovers funds from cardholders via statement billing.
- Acquirer settlement: The card network credits the acquirer's settlement account for net transactions processed. The acquirer then funds merchant accounts.
- Reconciliation: Daily settlement must reconcile: network settlement files vs. core banking postings vs. Federal Reserve account activity.
Chargebacks and Disputes
A chargeback is a forced reversal of a card transaction, initiated by the cardholder's issuer. Chargebacks are the card network's consumer protection mechanism — they are equivalent to ACH R10 (unauthorized) but with a much longer window and more complex process.
| Step | Action | Timeframe |
|---|---|---|
| 1. Cardholder Dispute | Cardholder contacts issuer to dispute a transaction | Up to 120 days from transaction date (Visa/Mastercard rules) |
| 2. Issuer Initiates Chargeback | Issuer sends chargeback to card network with reason code | Within network timeframe |
| 3. Network Routes to Acquirer | Card network debits acquirer's settlement account; routes chargeback to acquirer | T+3 to T+5 from initiation |
| 4. Acquirer Notifies Merchant | Acquirer passes chargeback to merchant with reason code and documentation request | Within acquirer SLA |
| 5. Merchant Representment | Merchant disputes the chargeback by providing evidence (receipt, delivery proof, authorization record) | Typically 20–30 days from chargeback |
| 6. Issuer Reviews / Arbitration | Issuer reviews representment; if rejected, can escalate to card network arbitration | Varies — can extend to 90+ days |
Common Chargeback Reason Codes
| Network | Code | Reason |
|---|---|---|
| Visa | 10.4 | Fraud — Card Absent Environment (CNP fraud) |
| Visa | 13.1 | Merchandise / Services Not Received |
| Visa | 13.7 | Cancelled Recurring Transaction |
| Mastercard | 4853 | Cardholder Dispute — Services Not Provided |
| Mastercard | 4863 | Cardholder Does Not Recognise (potential fraud) |
| Mastercard | 4834 | Point-of-Interaction Error |
Interchange Fees
Interchange is the fee paid by the acquirer (on behalf of the merchant) to the issuer for each card transaction. It is set by the card networks and varies by card type, transaction type, and merchant category.
- Consumer credit card: Typically 1.5%–2.5% of transaction value
- Debit card (regulated): Capped at $0.21 + 0.05% per transaction under the Durbin Amendment (Regulation II) for banks with assets ≥ $10 billion
- Debit card (exempt): Not capped — smaller issuers (under $10B assets) may charge higher debit interchange
- Corporate / purchasing cards: Higher interchange than consumer cards — typically 2.5%–3.5%