Checkout Blocker

Checkout-level blocking is server-side and cannot be bypassed from the browser. Built on Shopify Functions, it stops orders at the payment stage.

Available in the Enterprise plan and above.

Block by email pattern

1. Open Block checkout → Email rule.
2. Enter pattern (exact email or wildcard, e.g. *@tempmail.com).
3. Optional: custom error message shown at checkout.
4. Save.

Common patterns to block:

• *@tempmail.com, *@guerrillamail.com, *@10minutemail.com — disposable email
• *@yopmail.com, *@mailinator.com — temporary inbox
• Specific competitor email domains

Block by phone number

1. Open Block checkout → Phone rule.
2. Enter prefix (e.g. +1234) or exact number.
3. Save.

Useful for blocking known fraud phone prefixes from prior chargebacks.

Block by customer name

1. Open Block checkout → Name rule.
2. Enter exact name or partial match.
3. Save.

Block by address and zip code

1. Open Block checkout → Address rule.
2. Enter address keywords or ZIP code prefix.
3. Save.

Useful for:

• Freight-forwarder addresses (common chargeback indicator)
• ZIP codes you do not ship to
• High-risk specific addresses from prior fraud

Block by subtotal

1. Open Block checkout → Subtotal rule.
2. Enter condition: < $5, > $1000, etc.
3. Save.

Card-testers typically hit checkout with $0.01-$5 amounts. Block these to prevent payment-processor fee abuse.

Custom error message

Each rule supports a custom error displayed inside Shopify's checkout. Examples:

• "Sorry, we cannot process orders to this region."
• "Your shipping address is not eligible. Please contact support."
• "This payment method is not available for your account."

Whitelist exceptions

Add legitimate edge cases to the whitelist:

• Specific customer IDs
• Specific shipping addresses
• Tagged B2B accounts

See also

• Fraud filter setup
• Block IP
• VPN / Proxy blocker