Checkout Rules

Checkout Rules let you stop checkout with a clear customer-facing message when a cart should not be allowed to proceed. They use the same Payflow condition builder as Payment and Delivery Customizations, but the action is a validation error instead of hiding, renaming, or reordering a method.

Use Checkout Rules for cases like blocked postcodes, required company details for B2B orders, quantity limits, PO box restrictions, minimum subtotals, or high-value order checks.

Create a Checkout Rule

1. In Payflow, click Create customization and select Checkout Rule.
2. Give the rule a clear name, such as “Block PO boxes” or “Company required for invoice orders”.
3. Add conditions under When the following conditions are met. Use + Add AND condition for requirements in the same branch, or + Add OR group for alternative branches.
4. Write the message customers should see at checkout when the rule blocks progress.
5. Optional: add localized messages for languages your store supports.
6. Set the rule to Active or Testing, then click Save.

When the message appears

Checkout Rules run through Shopify’s checkout validation system. Payflow can surface validation during checkout interactions and at checkout completion, depending on the rule and the data Shopify has available at that moment.

Address timing still matters

Country-based rules can use Shopify’s checkout localization country before the full shipping address is entered. Address-specific conditions such as city, ZIP/postcode, province, street, and phone still wait for the customer to enter those shipping details.

Localized messages

If your store has multiple checkout languages, add translations for the validation message. Payflow chooses the message from the checkout language when possible, falls back to the base language, and then falls back to the default message.

Keep messages short and actionable. For example:

• We cannot ship to PO boxes. Please enter a street address.
• Company name is required for invoice orders.
• This order exceeds the maximum quantity for Cash on Delivery.

Testing

Use Testing status before exposing a new blocker to customers. Go through a real storefront checkout and make sure the rule blocks only the intended carts. If your rule depends on address details, fill in the full address while testing.

Related

Conditions All condition categories used by Checkout Rules.

Condition Sets Which conditions can be combined in one rule.

Rule not working? Troubleshooting activation, timing, targeting, and conflicts.

Limitations Shopify rule limits and other platform constraints.