Bad addresses, blocked before pay.
Real-time validation against postal authorities. Catches the typo, the wrong postcode, the bad apartment number — before the customer pays. Failed deliveries drop 38% on average.
NW1 6XE
The engine under your blocks.
Address Validator hits a real-time postal validation API as the customer types their shipping address. If the postcode doesn't match the city, we surface the issue inline. If the apartment number is missing on a known multi-unit, we prompt for it. The customer fixes errors before they hit pay — not at the courier, not on the doorstep. Stores using this typically see failed-delivery rates drop ~38%.
Three steps. Zero code.
Turn on validation
Single toggle in the Address Validator settings. We connect to USPS, Royal Mail, Deutsche Post, etc.
Configure strictness
Suggest (soft prompt), Warn (yellow flag), or Block (require fix before pay). Most stores use Warn.
Monitor the dashboard
See how many addresses got auto-corrected, how many were blocked, the failed-delivery rate over time.
Where it earns its keep.
Apartment-heavy regions
NYC, London, Mumbai — apartment numbers are routinely missed. Validation prompts for them inline.
International shipments
Cross-border addresses fail more. Validation against the destination country's postal authority catches the issue.
Subscription stores
Subscribers' addresses change. Validation on the first order catches issues that would compound monthly.
Common questions.
Something else we missed? Our support team replies within a day.
Ask support-
Which postal authorities do you check against?
USPS (US), Royal Mail (UK), Canada Post, Deutsche Post (DE), Australia Post, La Poste (FR), and 14 more. We add new authorities every quarter.
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Does this slow down checkout?
No. Validation is debounced — fires 500ms after the customer stops typing. The pay button is never blocked by an in-flight check.
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What if the API is down?
We fail open — the customer can still complete checkout. We log the failure so we can investigate.
Pairs well with these.
Checkout Rules
Trigger any action at checkout from any cart state — subtotal, tags, line items, country, customer segment. No flow tools, no third-party automation.
See the feature Platform featureHide Payment Methods
Filter Shopify's payment menu by cart contents, country, customer segment, or any rule. Hide COD on B2B carts. Block Klarna under €30. Stop chargebacks at the source.
See the feature Platform featureConditional Visibility
31 condition types — cart contents, customer state, geo, time, traffic source. Show a block only when it belongs. Hide it when it doesn't.
See the featureTurn on Address Validator in your next checkout.
Every platform feature is included on the 3-day trial. No credit card. No developer required.