Card Network
Infrastructure connecting merchants, acquirers, and issuers (Visa, Mastercard, Amex). Sets interchange fees and compliance rules.
Overview
What is Card Network?
Card networks (Visa, Mastercard, American Express, Discover) are the global infrastructures that connect merchants, acquiring banks, issuing banks, and cardholders - enabling card payments worldwide. Card networks establish operating rules, set interchange fees, manage authorization/settlement messaging, run fraud monitoring programs, and enforce compliance requirements. For high-risk merchants, understanding card network policies is critical because networks determine which businesses can accept cards through their acceptable use policies and chargeback monitoring programs.
Visa and Mastercard are "open loop" networks that don't issue cards or merchant accounts directly - they license banks to issue cards (issuing banks) and enable merchant processing (acquiring banks). This creates a four-party model: cardholder → issuing bank → card network → acquiring bank → merchant. High-risk merchant processing requires finding acquiring banks willing to sponsor you on Visa/Mastercard networks despite elevated risk profiles - most mainstream acquirers explicitly prohibit high-risk MCCs in their agreements with the networks.
American Express and Discover operate as "closed loop" networks - they issue cards directly to cardholders and process merchant transactions themselves, collapsing the four-party model into three parties. Amex/Discover have stricter merchant acceptance policies than Visa/Mastercard and routinely decline high-risk merchant applications. However, when approved, direct relationships sometimes offer advantages: faster dispute resolution, no acquirer middleman, and direct access to network expertise.
Network operating rules govern payment processing: chargeback reason codes and processes, fraud monitoring thresholds (Visa VDMP, Mastercard ECP), authorization response times, settlement timelines, and data security requirements (PCI DSS). High-risk merchants must understand network-specific rules - Visa's excessive chargeback threshold (1.5% and 1,000 chargebacks monthly) differs from Mastercard's (1.5% and 300 chargebacks) - requiring separate monitoring for each network. Network violations result in fines ($25K-100K per month), account termination, and TMF listing. MIDs' platform monitors network compliance across all relationships, alerting merchants before thresholds breach.
In depth
Everything you need to know.
When a customer makes a purchase, the network facilitates the transaction. During authorization, your gateway sends the request to your acquirer, which forwards to the card network (by card BIN). The network routes to the issuing bank, which approves or declines within 1-3 seconds. During settlement, networks receive batch files from acquirers. Networks calculate interchange fees, facilitate fund transfers between banks, and monitor for fraud patterns, chargeback rates, and violations.
Networks control card payment access. Monitoring programs (VDMP, ECP) trigger at 1.5% chargeback rate with $5K-25K monthly fines escalating to $100K+. Network rules differ: Visa counts chargebacks differently than Mastercard. A merchant at 1.4% with 800 monthly chargebacks (safe on Visa threshold of 1,000) might breach Mastercard limit of 300 chargebacks, entering Mastercard ECP while clean on Visa.
Illustrative example — not a specific client engagement.
- Supplement merchant tracked 1.3% overall, discovered Mastercard at 1.6% with 350 chargebacks (breaching ECP) while Visa was 1.1%. Entered ECP with $8K monthly fines.
- Gaming operator 80% on Visa. When Visa changed gaming rules, approvals dropped 78% to 64%. Lacked Mastercard volume. Rebuilding took 6 weeks.
- Dating platform MCC 7273 (2.8% interchange) reclassified to MCC 7379 (1.9%). At $2M monthly, saved $18K monthly ($216K annually).
- Monitor rates separately for Visa, Mastercard, Amex, Discover - different thresholds
- Maintain network-specific documentation: regulations, reason codes, thresholds
- Distribute transactions across networks to prevent over-concentration
- Review MCC annually - ensure code optimizes interchange
- Understand network-specific reason codes - each needs different evidence
- If entering monitoring: engage specialists - you have 90-180 days
- For $500K+ monthly: work with processors with direct network relationships
- Not monitoring networks separately - breaching Mastercard threshold (300) while under Visa (1,000)
- Assuming identical rules - using Visa codes for Mastercard disputes causes failures
- Ignoring Amex/Discover - missing 15-25% of payment methods
- Wrong MCC code - results in higher interchange or scrutiny
- Treating fines as operational costs - accepting $10K monthly instead of fixing issues
- Over-concentration on one network - creates risk when issues emerge
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