The summary.
NEVER STORE THE SECURITY CODE AFTER AUTHORISATION
Scheme rules prohibit it absolutely. Use tokens instead — and network tokens survive card reissue, which is a direct reduction in involuntary churn.
ACCEPTING ONLY INTERNATIONAL SCHEMES EXCLUDES MANY LOCAL CARDHOLDERS
The domestic scheme is cheaper and widely issued here, with limited international acceptance.
AUTHENTICATION'S REAL COMMERCIAL VALUE IS LIABILITY SHIFT
It converts unbounded fraud exposure into bounded exposure. Send rich data so more transactions pass without a challenge, since every challenge costs completion.
CARD TESTING MATTERS EVEN WHEN EVERY ATTEMPT FAILS
It consumes fees, raises decline ratios and attracts scheme attention. Rate-limit by address, device and card.
REVENUE LOST TO FRAUD REJECTION IS FREQUENTLY LARGER THAN THE FRAUD PREVENTED
Which is why optimising fraud to zero is the wrong target, and a review queue captures value that automatic rejection loses.
DECLINES ARE USUALLY THE LARGEST RECOVERABLE REVENUE LOSS IN A PAYMENT FLOW
Analyse decline codes by issuer, fix configuration and data quality first — they cost nothing.
