Write a Shopify checkout error message that tells customers why they cannot continue and what to do next. You can choose whether it appears at the top of checkout or beside a specific field.
Before you start
You need an active BlockCart subscription to save a checkout rule or changes to one.
Write the message
- Open a checkout rule from the Rules section on the BlockCart home page, or create a new checkout rule.
- Under Display, choose Target placement. Use Top of checkout for a problem with the cart or order. For a problem the customer can fix in a field, choose the matching field, such as Email or Postal code.
- In Error message, say what needs to change. For example, write “Add items to reach the $50 minimum order.” for a minimum subtotal rule. Avoid a message such as “Your order is invalid,” which gives the customer no next step.
- Check Preview to see the message and its selected placement. Select Save in the page header.

Example
| Rule input | Conditions | Error message | | -------------- | ----------------------------- | ----------------------------------------- | | Standard input | Cart subtotal is less than 50 | Add items to reach the $50 minimum order. |
For this rule, choose Top of checkout. The message explains the minimum and gives the customer a way to proceed. See Create your first checkout rule for the full setup.
Good to know
- Target placement also offers Phone, First name, Last name, Company, Address line 1, and City. Choose a field only when the customer can correct the problem there.
- Your message is shown as you wrote it. BlockCart does not translate merchant-written error messages for customers. Write it in a language your customers can understand.
- The message is fixed text. For a minimum order, state the threshold instead of a changing amount such as “Add $10 more.”
- Preview shows the message layout. To check when the rule actually blocks an order, test it in Shopify checkout. Several matching Live rules can show several errors.
