Kous Cash on Delivery Filter

Kous Cash on Delivery Filter helps store owners prevent repeat Cash on Delivery problems.

Main features:

• Block Cash on Delivery by exact email address.
• Block by normalized international phone number.
• Optional wildcard phone rules, such as 4477*.
• Block by privacy-preserving SHA-256 device fingerprint.
• Store IP addresses for investigation and correlation without blocking by IP alone.
• Hide or restore Cash on Delivery instantly during checkout with AJAX.
• Add a customer’s email, phone, IP address, and available device fingerprint from the WooCommerce order screen.
• Save the device fingerprint to new WooCommerce orders.
• Import and export blocklist entries as CSV.
• Export, clear, or delete individual attempt-history records.
• Search email and phone blocklists.
• Compatible with WooCommerce High-Performance Order Storage (HPOS).

International phone handling

Phone values are normalized without country-specific assumptions. Formatting characters are removed, and the international 00 access prefix is normalized so that +44... and 0044... match.

To prevent accidental partial blocking:

• Exact phone entries must contain 6 to 15 digits.
• Wildcard phone entries must contain 4 to 15 digits.
• Phone matching is exact unless an administrator explicitly adds a wildcard.
• Substring matching is never used.

IP address safety

IP addresses are stored for reference, export, and investigation. An IP address never removes Cash on Delivery by itself. This avoids false positives on mobile networks, carrier-grade NAT, offices, hotels, and shared connections.

Device fingerprints

The plugin creates a browser/device signal and stores only its SHA-256 hash. New WooCommerce orders save the hash as order metadata when checkout provides it. Blocking an order can then add the saved device hash to the blocklist.

A device fingerprint is a probabilistic browser signal, not a guaranteed unique hardware identifier. Browser changes, privacy settings, or different browsers may produce a different hash.

Privacy

Depending on configuration and use, this plugin can store:

• Customer email addresses.
• Customer phone numbers.
• IP addresses.
• Hashed browser/device fingerprints.
• User-agent strings in attempt history.

Store owners are responsible for providing appropriate privacy notices, determining a lawful basis, defining retention periods, and responding to data-subject requests under applicable laws.