You set in-checkout correction to “Require a fix or confirmation”, placed a test order with a bad address, watched the warning render, and paid anyway. The setting isn’t broken. Pausing checkout needs one more switch, and Shopify puts that switch in your hands, not ours.
The fix: one switch in the checkout editor
Shopify treats blocking checkout as a permission the merchant grants to each app block individually. Until you grant it, Shopify forces our prompt to let buyers through, so “Require a fix” behaves like “Suggest fixes”: the warning shows, the Pay button keeps working.
- Open the checkout editor (Settings → Checkout → Customize, or the button on the app’s Verification page).
- Click the Address Verification block inside checkout.
- In the Checkout behavior panel, turn on Allow app to block checkout.
- Save.
Then test again with a bad address. Hitting Pay now stops with the error pinned to the address field, and stays stopped until the buyer applies the fix or confirms the address as entered. While you’re in that panel, Include block in Shop Pay is worth turning on too; the setup guide covers what it does.
Two ways paying through is by design
The mode is called Require a fix or confirmation. A buyer who taps “Keep my address”, or dismisses the banner, has confirmed the address as entered and can pay. The pause exists to make buyers look at the address one more time, not to hold their order hostage; with carrier data, “unverifiable” sometimes means a brand-new building rather than a bad address, and the buyer knows which it is. If you want certain addresses stopped with no confirmation path, like PO Boxes you can’t ship to, use a Block rule instead. Those run on every plan and don’t accept “proceed anyway”.
And if our service was unreachable when the buyer entered the address, no prompt renders and checkout proceeds. The app fails open on purpose: a missed correction costs you one fix on the thank-you page, a broken checkout costs you the sale.