3D Secure (3DS)
An authentication protocol that adds an extra verification step to online card payments — typically a one-time code, biometric, or banking app push. VULK forces 3DS on every checkout to satisfy PSD2 and lock in the subscription mandate.
3D Secure (3DS)
3D Secure is the card-network protocol (Visa Secure, Mastercard Identity Check, American Express SafeKey) that lets the issuing bank challenge a card-not-present transaction with an additional authentication step — a code over SMS, a banking-app push, a fingerprint or Face ID confirmation. 3DS shifts liability for fraudulent chargebacks from the merchant to the issuer when the challenge succeeds, and is mandatory in the EEA under PSD2 for most online card payments.
VULK configures Stripe with request_three_d_secure: 'any' (not 'automatic') so the customer passes 3DS at every entry-point transaction — trial signup, plan upgrade, credit pack. This produces a clean PSD2 mandate, which is the prerequisite for off-session subscription renewals to succeed. The trade-off is a few extra seconds at signup; the upside is a 60-percentage-point reduction in past-due renewals.
PSD2 Mandate
The EU's Payment Services Directive 2 requires Strong Customer Authentication (SCA) on most card payments inside the EEA. A "mandate" stores the customer's authorized intent so future off-session charges can succeed without re-authenticating.
Adaptive Pricing
Stripe's feature that automatically presents prices in the customer's local currency at checkout, based on geo-detected location. VULK uses Adaptive Pricing on top of a EUR / USD geo-routed base price.