Guides

What we have had to work out about blocking checkouts on Shopify, written down with the sources we checked it against.

How to block a customer from ordering in ShopifyShopify has no native setting that stops a specific person from checking out. Here is what each built-in option actually does, why most of them act only after the order exists, and what runs during checkout itself.
Blocking disposable email domains at Shopify checkoutThrowaway email addresses are cheap to make and endless, so blocking them one at a time never finishes. What works is blocking at the domain, and knowing exactly where that stops working.
Hiding cash on delivery from risky buyers in ShopifyCash on delivery is the payment method fake orders abuse, because the buyer risks nothing. Hiding it selectively keeps it for the customers who pay, and Shopify's payment customization functions can do it without Shopify Payments.
Card testing at Shopify checkout: what actually helpsCard testing is automated, high volume, and rotates every identifier a rule could match. Here is honestly what checkout rules can and cannot do about it, and what to do instead.