Start with the order itself: open it in Shopify admin and look at its tags. That one glance usually identifies which of the cases below you’re in, because most “missed” addresses weren’t missed at all. They were caught, flagged, and shipped anyway.
1. It was caught, and the buyer said no
If the order carries the address-unverified tag, we caught it. The buyer saw the prompt and chose to keep their address, or never engaged with it. We don’t override buyers, and we don’t ship parcels; the tag was the handoff to you. The fix is a saved order filter on the tag so flagged orders get a human look before the label prints, or a Flow hold if fulfillment moves faster than you do.
2. The rule was on Warn, and you expected Block
This is the most common confusion in the category. Warn never stops checkout: the sale completes and the buyer is asked to fix the address afterward. If you wanted PO Boxes to be impossible rather than flagged, that rule needs to be set to Block at checkout in Settings. Warn vs Block covers how to choose, and why the defaults lean toward Warn.
3. The rule was Off
Policy rules (PO Box, military addresses, Packstation) ship Off because they’re shipping-policy decisions, not errors. If a PO Box surprised you, check Settings: the rule was probably never turned on.
4. The prompt had nowhere to render
Warn-level catches show up through the block you place in the checkout editor. If the block was never added to the thank-you page, verification still ran and still tagged the order, but the buyer never saw a prompt. The telltale combination: orders carry address-unverified tags, yet no buyer ever fixes anything. Step 2 of the setup guide fixes it in two minutes.
5. Validation was paused or unreachable
Two rarer cases, both visible at a glance. If your first 100 free orders ran out with no plan chosen, validation pauses and your dashboard shows a trial-ended banner; orders from that period were never checked. And if the verification service was briefly unreachable, the affected order went through untouched, tagged address-unverified. We fail open on purpose: our downtime should cost us a missed check, never cost you a sale.
6. The address was deliverable, just wrong
This is the honest limit of the whole category. Verification answers “can a carrier deliver here?”, not “is this where the buyer wants the parcel?” An old apartment the buyer moved out of is a perfectly deliverable address. A typo that lands on a real neighboring house number verifies clean. No address checker, ours included, can catch a valid address that’s simply the wrong one. The partial consolation: the most common wrong-but-valid source is stale wallet addresses, and the post-purchase prompt at least puts the address in front of the buyer one more time when anything about it looks off.
Still unexplained?
If the order has no tag, the rule was on, the block is placed, and the address is genuinely undeliverable, we want to see it. Email [email protected] with the order number and the address (or as much of it as you’re comfortable sharing), and we’ll trace exactly what the check returned.