
Visa requires cardholder email or phone number in all 3DS authentication requests as of August 12, 2024. This guide covers the specific data fields, format requirements, enforcement behavior, and liability shift implications for compliance teams validating vendor readiness.

Payment processing high availability is an architecture decision, not a server count. Here’s how uptime tiers, failover patterns, and multi-PSP routing determine whether your payment stack survives a processor outage.