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Auth Optimization

Prerequisites

Before optimizing auth rates, ensure you have:

  • Access to processor dashboard with auth rate and decline code visibility
  • Understanding of payments metrics and your current baseline
  • Familiarity with 3DS concepts (impacts auth rate)
  • Knowledge of your transaction types (CIT vs MIT, recurring vs one-time)
TL;DR
  • Baseline first: CNP e-commerce averages 85-90%, best-in-class hits 95%+—know yours before optimizing
  • Network tokens: +2-5% auth lift; tokenized credentials outperform raw PANs with issuers
  • Retry logic: Soft declines (51, 91) = retry in 3-5 days; hard declines (41, 43, 54) = never retry
  • 3DS exemptions: Request TRA, low-value, recurring exemptions where you qualify
  • Flag correctly: MIT vs. CIT matters—wrong flags = higher declines

Your auth rate is revenue. Every 1% improvement in approval rate is 1% more money. Most SMBs don't know their auth rate. When asked, they guess high.

Reality: CNP e-commerce averages 85-90% auth rates. Best-in-class hits 95%+. The gap between those numbers is real money you're not collecting.

What Matters

  1. Know your auth rate. Can't fix what you don't measure.
  2. Network tokens lift approval 2-5%. Tokenized credentials perform better with issuers.
  3. Retry logic matters. Wrong retries burn issuer trust. Right retries recover revenue.
  4. 3DS is a lever, not just compliance. Used well, it improves auth. Used badly, it kills conversion.
  5. Issuer declines have patterns. Learn your top decline reasons and fix the fixable ones.

Know Your Auth Rate

Before optimizing, baseline.

How to Calculate

Auth Rate = Approved Transactions / Total Attempted Transactions × 100

What's Normal

Business TypeTypical Auth RateBest-in-Class
E-commerce (US domestic)85-90%95%+
Subscription (initial)80-85%90%+
Subscription (recurring)90-95%97%+
Card-present (CP)98-99%99%+
International CNP75-85%90%+

If you're below "typical," there's low-hanging fruit.

Where to Find It

Check your processor dashboard. Look for:

  • "Authorization rate" or "Approval rate"
  • Filter by: card brand, card type, geography, transaction type
Ask Your Dev

"Where can I see our overall auth rate? Can I filter by card brand and geography?"


Network Tokens

Network tokens replace raw card numbers with network-issued credentials. Visa and Mastercard issue them. Your processor manages them.

What Network Tokens Fix

ProblemHow Tokens Help
Card reissuanceToken stays valid when card is replaced
Fraud screeningIssuers trust tokenized transactions more
Auth rates2-5% lift on tokenized vs. raw PAN

How They Work

  1. Customer enters card at checkout
  2. Processor requests token from Visa/Mastercard
  3. Token is stored instead of card number
  4. Future transactions use the token
  5. Network keeps token mapped to current card credentials

When to Use

  • Recurring billing (tokens stay valid through card updates)
  • Repeat customers (stored payment methods)
  • Digital wallets (Apple Pay/Google Pay are tokenized)

Operator Questions

Ask Your Dev

"Are we using network tokens or raw PANs for stored cards? If raw PANs, can we migrate to network tokens?"

Network tokens are free or low-cost from most processors. There's little reason not to use them.


Card-on-File Transaction Flags

How you flag a transaction affects auth rates.

MIT vs. CIT

TypeMeaningExample
CIT (Customer-Initiated)Customer is present for the transactionOne-time purchase, initial subscription signup
MIT (Merchant-Initiated)Merchant charges without customer presentRecurring billing, delayed charges

Why Flagging Matters

Issuers apply different rules:

  • CIT may require 3DS challenge
  • MIT skips 3DS but requires prior consent
  • Wrong flag = higher declines

Common Flags

FlagUse Case
recurringSubscription billing
installmentScheduled payment series
unscheduledVariable charges on stored card
resubmissionRetry of previously declined
Ask Your Dev

"What transaction flags are we sending on recurring charges? Are we flagging MIT correctly?"


Retry Logic Rules

Retrying declines is a double-edged sword. Do it right, recover revenue. Do it wrong, damage your issuer reputation.

What's Allowed

Decline TypeRetry?Strategy
Soft decline (insufficient funds)YesWait 3-5 days, retry around payday
Issuer unavailableYesWait 4-24 hours
Velocity limit exceededMaybeWait 24 hours, try once
Card expiredNoRequest new card
Do not honorOnceTry once more, then stop
Fraud/stolenNeverStop immediately

What Burns You

  • Retrying hard declines (stolen, invalid, closed)
  • Excessive retries (more than 2-3 on same card)
  • Immediate retries (no wait time between attempts)
  • Ignoring decline codes

Issuer View

We track merchants who repeatedly hit declined cards. Excessive retry behavior is a fraud signal. Merchants with bad retry patterns see lower auth rates across all their transactions.

Retry Velocity Limits

Card networks have rules:

  • Visa: Max 15 retries in 30 days per card
  • Mastercard: Similar limits with monitoring

Exceeding these can result in fines or processing restrictions.


Hard vs. Soft Decline Logic

Soft Declines: Retry-Eligible

Decline CodeMeaningRetry Strategy
51Insufficient fundsWait 3-5 days
91Issuer unavailableWait 4-24 hours
85Card not activatedWait 1-2 days
61Exceeds withdrawal limitWait a few days
65Activity limit exceededWait 24 hours

Hard Declines: Do Not Retry

Decline CodeMeaningAction
05Do not honorTry once more max
14Invalid card numberStop, request new card
41Lost cardStop immediately
43Stolen cardStop immediately
54Expired cardStop, request new card
57Function not permittedStop, different card needed

Processor Translation

Different processors return different codes. Your processor should map network codes to actionable categories. If they don't, ask for a mapping document.

Ask Your Dev

"Are we handling soft vs. hard declines differently? Can I see how we're categorizing decline codes?"


3DS Optimization

3DS (3D Secure) adds an authentication step. It can help or hurt depending on how you use it.

3DS Impact Reality

ScenarioAuth Rate ImpactLiability Shift
3DS challenge, customer completes-5 to -15% conversionYes
3DS frictionless (no challenge)Neutral to +1%Yes
No 3DSBaselineNo

When 3DS Helps

  • High-risk transactions (new customer, new shipping address)
  • International transactions (required in EU, recommended elsewhere)
  • High-ticket purchases
  • Transactions you'd otherwise decline

When 3DS Hurts

  • Low-risk returning customers
  • Mobile transactions (challenge UX is painful)
  • Guest checkout (adds friction to already-fragile flow)

3DS Exemptions

Request exemptions when you qualify:

ExemptionCriteriaBest For
TRA (Transaction Risk Analysis)Low-risk based on your fraud rateLow-risk merchants
Low-valueUnder €30 (EU)Small purchases
RecurringSubsequent subscription chargesRecurring billing
Trusted beneficiaryCustomer whitelisted the merchantReturning customers
Ask Your Dev

"Are we requesting 3DS exemptions where we qualify? What's our frictionless vs. challenge rate?"

3DS2 vs. 3DS1

3DS2 (current) supports frictionless authentication. 3DS1 (legacy) always challenged. If you're still on 3DS1, upgrade. The auth rate difference is significant.

Related: 3DS Deep Dive


Idempotency: Why Customers Get Charged Twice

Double charges happen when the same transaction is submitted multiple times.

How It Happens

CauseScenario
Customer retryCustomer clicks "Pay" twice
Network retryNetwork retransmits due to timeout
Merchant retryYour system retries on ambiguous response

The Fix: Idempotency Keys

Idempotency keys are unique identifiers attached to each payment attempt. If the same key is submitted twice, the processor returns the original result instead of charging again.

Operator Impact

Without idempotency:

  • Duplicate charges
  • Customer complaints
  • Support tickets
  • Chargebacks ("I was charged twice!")

How to Verify

Ask Your Dev

"Are we using idempotency keys for payment attempts? Show me the implementation."

This is not code you need to understand. It's a question to ask.


Issuer Decline Patterns

Declines aren't random. They cluster by cause.

Common Patterns and Fixes

PatternCauseFix
High decline rate on one BINIssuer-specific policyContact issuer, adjust fraud rules
International cards decliningCross-border frictionConsider local acquiring
First-time customers declining moreNew card, no historyAdd 3DS for liability shift
Weekend declines higherBank staffing/limitsAdjust retry timing
High declines on specific amountVelocity or limit triggersVary transaction amounts

Decline Code Analysis

Run a monthly report:

  1. Pull all declines
  2. Group by decline code
  3. Identify top 5 codes by volume
  4. Research causes and fixes for each

Issuer View

The top 3 reasons we decline:

  1. Suspected fraud (velocity, geography, mismatch)
  2. Insufficient funds
  3. Card restrictions (international, e-commerce)

Merchants who address #1 (better fraud signals) see the biggest lift.


Test to Run

3-week auth rate improvement:

Week 1: Baseline.

  • Record current overall auth rate
  • Pull decline code breakdown
  • Identify top 5 decline reasons

Week 2: Implement fixes.

  • Adjust retry logic for soft declines
  • Request 3DS exemptions where qualifying
  • Verify idempotency is in place

Week 3: Measure.

  • Compare auth rate to baseline
  • Track decline code distribution

Success criteria: 1-3% improvement in overall auth rate.


Scale Callout

VolumeFocus
Under $100k/moKnow your auth rate. Ensure basic retry logic is sane. Enable 3DS for high-risk only.
$100k-$1M/moMonthly decline code analysis. 3DS exemption strategy. Network token migration.
Over $1M/moIssuer-level optimization. Dedicated auth rate monitoring. A/B test 3DS strategies. Multiple processor routing for auth lift.

Where This Breaks

  1. International transactions. Cross-border declines are structurally higher. Local acquiring helps but adds complexity.

  2. High-risk MCCs. Some industries have elevated decline rates regardless of optimization. Issuers are more conservative.

  3. New merchants without history. Issuers trust merchants with track records. New accounts face higher decline rates until they build history.


Analyst Layer: Metrics to Track

MetricWhat It Tells YouTarget
Overall auth rateBaseline health> 90% US domestic CNP
Auth rate by card brandNetwork-specific issuesVisa/MC should be similar
Auth rate by geographyCross-border frictionDomestic > international
Soft vs. hard decline ratioRetry opportunitySoft should be > 50% of declines
Retry success rateRetry logic effectiveness> 20% of soft declines recovered
3DS challenge rateFriction level< 20% of 3DS transactions challenged
3DS conversion rateChallenge completion> 80% complete challenge

Trend Over Snapshot

Auth rate fluctuates. Track weekly trend, not daily snapshot.

A 0.5% week-over-week decline is a signal. A 0.5% daily swing is noise.


Next Steps

Just starting auth optimization?

  1. Pull your current auth rate from your processor dashboard → Baseline before optimizing
  2. Identify your top 5 decline codes → Focus fixes on highest-impact issues
  3. Check if you're using network tokens → If not, migrate stored cards to tokens

Ready to improve?

  1. Follow the increase auth rates playbook → Step-by-step optimization
  2. Implement smart retry logic → Recover soft declines without burning issuer trust
  3. Review your 3DS strategy → Optimize exemptions for low-risk transactions

Already optimizing?

  1. Set up weekly auth rate monitoring → Track trends, not snapshots
  2. Segment by card brand and geography → Find specific weak spots
  3. Consider multi-processor routing → Route to best-performing processor by issuer