Checkout Guard helps merchants prevent invalid orders before they reach checkout. It allows merchants to define rules that block carts with incompatible items, such as mixed pre-orders and in-stock products, conflicting shipping types, or fulfillment restrictions. Rules are enforced at checkout so invalid orders are stopped before payment. This helps reduce fulfillment errors, refunds, and manual order fixes while giving merchants clear visibility into blocked checkouts.

• Block pre-order + in-stock items being purchased together
• Block carts with conflicting shipping or fulfillment methods
• Block carts with products that must be purchased alone
• Block invalid or incompatible product combinations