Reference
Quick lookups. No explanations, just the data you need.
Typical Range Disclaimer
All ranges marked "Typical" in this reference section assume US domestic transactions with standard risk profiles. Your actual numbers will vary based on your MCC, customer base, transaction mix, and geography.
What's Not Covered Yet
This site doesn't yet cover in depth:
- Marketplace/PayFac operations and compliance
- Crypto and stablecoin payments
- Cross-border payout optimization
- Card program management (issuer-side deep dives)
These may be added in future updates.
Popular
❌
Decline Codes Popular
Why transactions fail
🔢
Reason Codes Popular
Chargeback category lookup
⏰
Time Frames
Response deadlines by network
📊
Benchmarks
What "good" looks like
📖
Glossary
Definitions and terminology
What You Need Right Now
❓
"Why was this declined?"
Decline codes explain authorization failures
❓
"What's this reason code?"
Reason codes explain chargeback categories
❓
"When do I have to respond?"
Deadlines by network and stage
❓
"What does this mean?"
Acronyms: AVS, CVV, ARN, TC40...
Reason Codes by Network
Every chargeback has a code. The code tells you why and what evidence you need.
💳
Visa
10.4 (fraud), 13.1 (not received), 13.2 (cancelled recurring)
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Mastercard
4837 (fraud), 4853 (dispute), 4834 (POI error)
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Amex
F29 (fraud), C08 (goods not received), C28 (cancelled recurring)
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Discover
UA02 (fraud), RG (not received), AP (recurring)
Decline Codes
Decline Codes - Authorization decline reasons and what to do about them.
Common ones you'll see constantly:
- 05 (Do Not Honor) - Generic decline, retry might work
- 51 (Insufficient Funds) - Card maxed out
- 14 (Invalid Card Number) - Typo or test card
- 54 (Expired Card) - Update card on file
ACH Return Codes
ACH Return Codes - Why ACH transactions bounce.
The ones that matter:
- R01 (Insufficient Funds) - Most common, can retry
- R10 (Unauthorized) - Chargeback equivalent, 60 days
- R29 (Corporate Unauthorized) - Same as R10, corporate account
Response Deadlines
Time Frames - Miss these and you automatically lose.
| Network | Representment | Pre-Arb | Arbitration |
|---|---|---|---|
| Visa | 30 days | 30 days | 10 days |
| Mastercard | 45 days | 30 days | 10 days |
| Amex | 20 days | 45 days | — |
| Discover | 20 days | — | — |
Terminology
📖
Glossary
Definitions and terminology
🔤
Acronyms
AVS, CVV, ARN, TC40, etc.
🔍
Fraud Classification
Identify fraud types and responses
Next Steps
Looking up a code?
- Decline Codes - Auth failures
- Reason Codes - Chargeback categories
- ACH Return Codes - Bank returns
Need context?
- Payments Overview - How transactions work
- Chargebacks Overview - Dispute process
- Fraud Types - Threat landscape
Building a process?
- Benchmarks - What "good" looks like
- Time Frames - Critical deadlines
- Experimentation - Test safely
See Also
- Fraud Prevention - Stopping fraud
- Operations - Operational processes
- Playbooks - Step-by-step guides
- Network Programs - VAMP, ECM thresholds
- 3D Secure - Authentication
- AVS & CVV - Verification signals
- Chargeback Metrics - Tracking disputes
- Fraud Metrics - Measuring performance