BlockCart lets you create Shopify checkout rules that stop orders that do not meet your requirements and show customers an error. You can also use it to change the payment methods customers see. Your rules run natively inside Shopify checkout, with no theme code to edit.
What can you do with BlockCart?
| Rule | What it does | Example | | -------------------------------- | ---------------------------------------------------------------------------------- | ------------------------------------------------------ | | Cart and checkout validation | Checks an order against your requirements and shows an error if it cannot proceed. | Stop an order when its subtotal is below your minimum. | | Payment customization | Changes which payment methods are available or how they appear. | Hide a payment method for a particular cart value. |
How do checkout rules work?
With Shopify checkout validation, you set conditions that describe an order you want to stop. For example, you can set a condition for a cart subtotal below your minimum. When a customer's cart or checkout matches, BlockCart's rule tells Shopify checkout to stop the action and show the error message you wrote. The customer sees the problem before completing the order.
You can also use Shopify cart validation to show an error while the customer interacts with the cart. The rule runs only at the steps you choose. For the setup steps, see Create your first checkout rule.
How do payment rules work?
Payment rules use conditions too, but their result is different. When a customer's order matches, Shopify checkout changes the payment methods shown to that customer. You can hide selected methods, hide all methods, or show only selected methods. You can move methods to the top, bottom, or a chosen position; put them in a preferred order; or rename one method. For example, you could hide a method when the cart total is above an amount you set.
Payment rules do not reject an order with a checkout validation error. They change payment choices instead. Take care with a rule that hides all methods: it can leave the customer without a way to pay and prevent checkout completion. See What payment rules can do for more detail.
What you need
You need an active BlockCart subscription to create or save checkout and payment rules. A development store without an active subscription can open BlockCart and look at its pages and saved rules, but it cannot create or save rules. The app shows a billing prompt when you need to subscribe.
If your subscription ends, your previously saved rules stay in BlockCart. BlockCart removes the active checkout and payment changes from Shopify, so those rules stop running there. When you subscribe again, BlockCart tries to restore active rules. Check your rules after subscribing to confirm they are running as expected.