Skip to main content

Card Networks

TL;DR
  • Your processor moves the money. The networks write the rules and levy the fines
  • Visa is roughly 50% of US volume, Mastercard roughly 25%. Amex and Discover are smaller and run their own rulebooks
  • Response windows differ by network: Visa 30 days, Mastercard 45, Amex 20, Discover 30
  • When a threshold letter lands, work out whether it's the network or your processor talking. The fix is different

Your processor moves the money. The networks make the rules and hand out the fines. Breach a chargeback threshold and it's Visa or Mastercard coming for you, not your processor. Get that backwards and you'll spend a week arguing with the wrong people.

The Four Major Networks​

💳
Visa
  • Market share: ~50% US, ~40% global
  • Chargeback threshold: ~0.9% (processor-enforced) / VAMP 1.5% (2.2% in CEMEA)
  • Response window: 30 days
  • Type: Open-loop network
🔴
Mastercard
  • Market share: ~25% US, ~35% global
  • Chargeback threshold: ECM at 100-299 chargebacks AND 1.50-2.99%
  • Response window: 45 days
  • Type: Open-loop network
🔵
American Express
  • Market share: ~15-20% US, ~10% global
  • Chargeback threshold: none published
  • Response window: 20 days
  • Type: Closed-loop network
🟠
Discover
  • Market share: ~7-10% US, under 1% global
  • Chargeback threshold: none published
  • Response window: 20-30 days
  • Type: Closed-loop network

Open-Loop vs Closed-Loop​

Open-Loop (Visa, Mastercard)​

Characteristics:

  • Network is separate from issuers and acquirers
  • Many banks issue Visa/Mastercard cards
  • Competition among issuers
  • Network sets rules but doesn't compete

Closed-Loop (Amex, Discover)​

Characteristics:

  • One company does everything
  • Issues own cards (mostly)
  • Operates the network
  • Often handles acquiring
  • More control, less competition

What this means for merchants:

  • Open-loop: Rules are negotiated between many parties
  • Closed-loop: One company makes all decisions

Network Comparison for Merchants​

FactorVisaMastercardAmexDiscover
Chargeback threshold1.5% VAMP (2.2% CEMEA), on 1,500+ events100-299 AND 1.50-2.99% (ECM)None publishedNone published
Monitoring programsVAMPACMP: ECM, HECM, EFM. Plus SMMPInternal, no numbersInternal, no numbers
Response window30 days45 days20 days20-30 days
Reason code format2-digit (10.4)4-digit (4837)Letter (F29)Letter (UA02)
Win rate (typical)40-50%40-50%30-40%30-40%
Network feesNot published. This site assumes 0.14% + $0.02Not published. Same assumptionNot publishedNot published
International presenceHighHighMediumLow

Nobody publishes an assessment schedule. Not Visa, not Mastercard, not Amex, not Discover. The 0.13-0.15% you'll see quoted everywhere traces to processor statements and vendor blogs, never to a network document. This site carries a single assumed figure and says so: 0.14% + $0.02, derived here.

Two of the four won't tell you where the line is. Visa and Mastercard at least leak numbers through acquirers. Amex and Discover don't have numbers to leak. Amex acts when your volume looks "disproportionate" to it. Discover reserves the call to "our sole discretion". So on those two, your acquirer's house limit is the only line that exists.

Which Network Matters Most?​

By Volume (Your Processor Reports This)​

Typical US merchant transaction mix:

  • Visa: 50-55%
  • Mastercard: 25-30%
  • Amex: 10-15%
  • Discover: 5-10%

Where to focus:

  • Monitor Visa first (most volume, strictest thresholds)
  • Monitor Mastercard second (second most volume)
  • Amex and Discover publish no threshold at all, so there's nothing to monitor against. Watch your acquirer's limit instead

By International​

If you're selling internationally:

  • Visa: Dominant globally
  • Mastercard: Strong in EU, LATAM, Asia
  • Amex: US and premium segments only
  • Discover: Irrelevant internationally

International merchants: Visa + Mastercard = 95%+ of your international volume.

How to Work With Networks (Hint: You Don't)​

You never contact networks directly. Everything goes through your processor:

Want to...Who You Contact
Dispute a chargebackYour processor
Ask about monitoring programsYour processor
Request threshold exceptionYour processor (they ask network)
Report fraud clusterYour processor
File for arbitrationYour processor

Networks work B2B (bank-to-bank). Merchants are excluded from direct communication.

Exception: MATCH listings. There's no self-service lookup, but the acquirer that listed you must give you the listing ICA and the reason code on request, and must respond to a removal request within 30 calendar days. Mastercard states you don't need a lawyer for that request.

Network-Specific Strategies​

Visa: Most Strict, Most Important​

Strategy:

  • Monitor Visa ratio weekly (0.9% threshold is low)
  • Implement CE 3.0 for Visa fraud disputes
  • Set internal alarm at 0.65% (VAMP early warning)
  • Respond to Visa disputes within 15 days (even though you have 30)

Priority: Highest - Visa breaches hurt most

Mastercard: More Forgiving​

Strategy:

  • Monitor Mastercard separately (1.5% ECM threshold)
  • Watch for "prior month" calculation quirks
  • Use full 45-day window if needed
  • Implement Ethoca alerts (Mastercard-owned)

Priority: High - second most volume

Amex: Inquiry-Focused​

Strategy:

  • Respond to inquiries within 48 hours (prevents chargebacks)
  • Accept that win rates are lower (30-40%)
  • Use same evidence as Visa/MC
  • Track 20-day deadlines carefully

Priority: Medium - lower volume, higher AOV

Discover: Low Volume, Low Risk​

Strategy:

  • Treat like Visa/MC disputes (same evidence)
  • Don't forget 20-30 day windows
  • Low volume = rarely breach thresholds

Priority: Low - unless Discover is unusually high % for you

Test to Run​

Multi-network monitoring setup:

Week 1: Build tracking

  1. Create spreadsheet with columns:
    • Total disputes this month
    • Visa disputes | Visa ratio
    • MC disputes | MC ratio
    • Amex disputes | Amex ratio
    • Discover disputes | Discover ratio

Week 2: Set thresholds 2. Add threshold rows. Only two of these come from a network:

  • Visa: 1.5% VAMP merchant excessive, on 1,500+ events. Your processor will act nearer 0.9%
  • Mastercard: 100-299 chargebacks AND 1.50-2.99% (ECM). Track the count and the ratio as two rows
  • Amex: ask your acquirer. Amex publishes nothing
  • Discover: ask your acquirer. Discover publishes nothing

Don't put a made-up number in the Amex and Discover rows. Put your acquirer's house limit there, in writing, or leave them blank. A fake threshold that nobody enforces is worse than an empty cell, because you'll manage to it.

Week 3: Alert system 3. Calculate distance to threshold for each network 4. Set alerts at:

  • Visa: 0.65% (processor early warning)
  • Mastercard: 75 chargebacks, or a 1.20% ratio, whichever comes first
  • Amex and Discover: whatever your acquirer told you, minus a third

Success criteria: Weekly monitoring across all four networks, alerts before breaching.

Scale Callout​

Under $100K/month:

  • Track total ratio (all networks combined)
  • Don't split by network yet (volume too low)
  • Unlikely to breach count thresholds

$100K-$500K/month:

  • Start tracking Visa and Mastercard separately
  • Can breach count thresholds (100/month)
  • Amex/Discover still low priority

$500K-$1M/month:

  • Track all four networks separately
  • Visa ratio is your biggest risk
  • Implement network-specific alerts

Over $1M/month:

  • Dedicated monitoring per network
  • Network-specific prevention strategies
  • Consider chargeback guarantee services

Where This Breaks​

  1. Digital wallet confusion: Apple Pay and Google Pay transactions can be any network. Check your statements, because you can't tell from the wallet.

  2. Network rules change: Visa and Mastercard update rules quarterly. Your processor should inform you, but they don't always.

  3. Processor errors in reporting: Your processor reports your ratios to the networks. If they get it wrong, you're the one who pays. Check their math.

  4. Multi-processor complexity: Each processor reports separately, so nobody's aggregating across them but you.

  5. International vs domestic rules: Networks have different rules for cross-border transactions. Research before expanding.

Next Steps​

New to network rules?

  1. Read Payment Ecosystem first
  2. Understand who does what
  3. Then dive into individual network pages

Monitoring chargeback ratios?

  1. Chargeback Monitoring Thresholds - All programs
  2. Zero Point Nine Panic - Crisis response
  3. Network Programs Reference - Full details

Dealing with network fines?

  1. MATCH/TMF List - Termination database
  2. Reduce Chargebacks Fast - Emergency playbook
  3. Chargeback Prevention - Long-term strategy

See Also​

Last updated on