Wrong or incomplete delivery addresses cause returns, support tickets and refunds. Zvanta Address Validator checks every order in checkout — including express and wallet checkouts — and stops undeliverable addresses before the order is placed. After purchase it verifies addresses against official postal registers, shows the customer a ready correction and can fix clear errors automatically. It never changes an address it is not sure about. Every rule ships with a recommended default.

• Blocks bad addresses in checkout, including express and wallet checkouts
• 24 rules: missing house number, postal code format, PO boxes, lockers, test data
• Checks against official postal registers for DE, AT, CH, LI and PL
• Order tags per error type, fulfillment holds and address statistics
• Buyer messages in the customer's language; panel in English, German and Polish

Zvanta Blocklist is a hard customer blocklist that works inside checkout. Add an email, phone or delivery address and the order simply cannot be placed — including express checkouts, where banner apps never load. Smart matching catches Gmail aliases, phone prefixes and spelling tricks. Orders that slip through other channels are tagged instantly and can be auto-cancelled with a full refund. Buyers only ever see a neutral message. Your list is encrypted at rest; GDPR erasure is automatic.

• Hard checkout block by email, phone or address — works in express checkout too
• Smart matching: Gmail aliases, phone prefixes and typos cannot dodge the list
• Auto-cancel with refund for orders that slip through the checkout block
• One-click „block from order #” plus CSV import of existing lists
• Neutral decline message — buyers never learn they are listed (GDPR-safe)