PO Box addresses

What this rule does

If you print a UPS or FedEx label for a PO Box order, the package comes back, and the carrier may add a correction fee on top of the return shipping. The rule spots PO Box addresses the moment your buyer enters one, in all the usual spellings and a few international disguises.

What it catches

• PO Box 123 and P.O. Box 123
• POB 123 and Post Office Box 123
• Postfach 200 (the German format)
• Apartado 50 (the Spanish format)

It matches PO Box formats, not every address containing the word box. An order for 123 Boxwood Lane goes through untouched.

What your buyer sees

Set to Block at checkout

Your buyer sees the message right at the address field, inside Shopify's own checkout, before payment. They fix the address and pay. The check runs inside checkout itself, so it adds no waiting time and nothing changes in your theme. Our default message:

You can replace it with your own wording in the rule's settings.

Set to Warn after purchase

The sale completes normally. On the order confirmation page we ask the buyer to double-check the address, and when we have a verified fix they can apply it with one tap. Orders with unresolved address problems are tagged address-unverified in your admin so you can catch them before fulfillment. This mode works with every payment method, including Apple Pay and Google Pay express checkouts.

If a check can't run for any reason, the order goes through untouched. We never hold up a sale on our own uptime.

Set it up

Open Address Verifier in your Shopify admin, go to Settings, and pick PO Box addresses. Choose Off, Warn after purchase, or Block at checkout, write your own checkout message if you want one, and save. Changes are live on your next checkout. No deploy, no theme edit.

New installs start with this rule Off. Blocking is a shipping policy decision, so you make it, not us.