"I have AddressHero installed, but an order without a house number just went through." This is our most common support request, and in almost every case one of the causes below is the answer. Work through the list from the top.
Express checkouts (Apple Pay, Google Pay, PayPal Express) skip the checkout form entirely, so no in-checkout rule can block them. This is the single most common cause. These orders ARE caught by the post-checkout validation. See Express wallets and landing-page checkouts.
On standard plans, only Shopify-integrated payments (Shopify Payments, regular PayPal) can be blocked. Klarna, iDEAL, bank transfer and similar cannot. On Plus, the additional checkout extension covers them. See Blocking invalid checkouts (Plus and non-Plus).
The checkbox that allows AddressHero to block the checkout must be enabled in the Shopify checkout editor. Without it, rules evaluate but nothing blocks.
Check that "Validate in checkout" is active and the specific rule (for example missing house number) is enabled. Settings occasionally get reset during theme or checkout profile changes, so re-check after such changes.
In the checkout editor, the extension named "Address Validation" must be placed. An extension block labeled "Added Manually" is not the validation.
Shopify's validation function limit is exceeded above 9 active languages, and the in-checkout validation stops entirely. Reduce active languages.
Two honest limits: a missing street NAME is not checked (Shopify handles required fields), and whether a house number is CORRECT can never be verified, only whether one is present. Placeholder-style entries that look like a valid format also pass the format check; the post-checkout database validation is what catches them.
The post-checkout flow flags the address and asks the customer, but we cannot force a reaction. If the customer closes the tab, the address stays as entered. Mitigations: automatic correction for clear errors, the reminder email, and the on-hold workflow so such orders never reach fulfillment silently. See Customer emails and on-hold orders.
"Unconfirmed house number" and similar low-confidence findings do not block or correct by default (the address is potentially valid). You can enable stricter handling per error type, including holds.
External funnels that jump straight to payment behave like express checkouts: no in-checkout step, post-checkout covers it.
Contact us via support with your store URL and the order number. We can see for every single order what was checked and why it passed.
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