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An independent studio building Shopify apps that respect your data — no third-party services, no customer data retained. Its first app, Checkout Guard, blocks PO boxes and enforces your cart limits at Shopify checkout.
Checkout Guard
Checkout Guard adds the address and cart rules Shopify checkout doesn't enforce on its own — on any plan, without theme code.
- PO box & address blocking — reject orders shipping to PO boxes or addresses you don't serve, with your own message at checkout.
- Order limits — minimum/maximum quantity per product and minimum/maximum cart total.
- Validation health — your Shopify admin shows whether the validation is active, not applied, or running fail-open (the order goes through if the check can't run), so a rule that quietly stops applying doesn't go unnoticed.
Pricing: 9.99 USD per month, with a 30-day free trial.
Checkout Guard reports the validation's health based on what Shopify's API exposes; it is not a guarantee that every order was checked. We show you when it drifts — we don't claim it always works. Express/accelerated checkouts (e.g. Shop Pay) can bypass cart validation; this Shopify behavior is disclosed inside the admin.
Frequently asked questions
How do I block PO boxes at Shopify checkout?
Checkout Guard rejects orders shipping to a PO box and shows your message at checkout, on any Shopify plan and without theme code.
How much does Checkout Guard cost?
Checkout Guard costs 9.99 USD per month, with a 30-day free trial.
Coming soon to the Shopify App Store.