PO box comparison
Block PO boxes: native shipping-rate hide vs checkout validation vs AddressFence
Native Shopify can block a PO Box on shipping, and since the 17 June 2026 changelog Checkout Blocks address validation is available to all merchants for that ship-to job, but billing is not covered. Shopify Help names PO box among the types you can block. AddressFence documents billing-address rules — built-in checkout rules cannot target billing at all — and merchants should not block every PO Box. Test any address in the simulator before publishing, with one-click rollback.
Free check first: PO box and street number address checker runs in your browser and sends nothing. Paste addresses and see which look like a PO box or lack a street number.
Live listing: apps.shopify.com/address-guard (handle address-guard). The older Address Blocker app sunset on 31 August 2026. Publish only the address types the store policy needs.
Related: B2B PO Guard — Require PO — B2B purchase order number required at company checkout.
How-to for the billing job: PO box blocker for the billing address. Adjacent: B2B purchase order · staff permissions audit.
Which public listings mention billing or a street-number check: PO box blocker apps: which ones check the billing address.
Three controls, three surfaces
Three controls see three surfaces: native shipping-rate hide decides whether a carrier offers a rate to a ship-to and never reads billing, while Checkout Blocks can block a PO Box on shipping for every merchant since 17 June 2026 but does not cover billing. AddressFence checkout validation can target billingAddress if the published function is set that way.
| Control | What it sees | PO Box on billing? |
|---|---|---|
| Native shipping-rate hide | Whether a carrier or delivery profile offers a rate to that ship-to | No. Billing is never rated. Digital carts have no shipping rates. |
| Native checkout validation (Checkout Blocks, all merchants since 17 June 2026) | Shipping address types (PO Box and similar types you enable) | No. Billing address is not covered. Shipping can be blocked natively. |
| AddressFence checkout validation | Billing-address rules at checkout (built-in checkout rules cannot target billing at all) | Yes — billing-address rules. Still only the types the merchant enables. |
Native checkout can block non-compliant shipping addresses since 17 June 2026. AddressFence pages on momiji-space only document billing-address rules and require a street number after Address Blocker sunset on 31 August 2026. Test any address in the simulator before publishing, with one-click rollback. Merchants should not block every PO Box.
When you should not block all of them
A store that sells to people who only have a PO Box for delivery should keep ship-to boxes available. Blocking every PO Box, locker, military, or diplomatic type because a shipping-format list includes them is the wrong default. AddressFence does not decide that policy; the merchant enables types and publishes.
- Leave PO Box shipping on when parcels really go to a box.
- Do not copy locker, military, diplomatic, or USPS gopost® types onto billing unless that is the written policy.
- Do not force shipping = billing just to “catch” a box. That blocks gift checkouts and still lets a matched PO Box through.
- Digital or shipping-not-required carts never run a shipping-only rule. Decide whether billing is in scope at all before you publish.
Where AddressFence still differs
Use native Checkout Blocks when the job is a non-compliant shipping address — available to all merchants since 17 June 2026. Use AddressFence when the job is a field error on billing, or the sibling street-number check after Address Blocker sunset on 31 August 2026. Do not block every PO Box.
| Path | Still missing |
|---|---|
| Rate hide | No checkout field error. No billing read. Buyer can still complete checkout if another rate or a digital cart exists. |
| Native shipping format validation | Does block a PO Box on shipping. Does not cover billing. A street ship-to plus a PO Box on the card still passes. |
| AddressFence | Does not hide carrier rates. Does not replace AVS. Does not block types you left off. Not a fraud guarantee. |
Street-number is a sibling job on the same listing: “Require a street number - the Address Blocker rule that was not migrated.” Test any address in the simulator before publishing, with one-click rollback. The older Address Blocker app that some stores used for that check sunset on 31 August 2026. It is not a shipping-rate hide, and it is not a reason to block every PO Box. After the sunset: Require a street number after the Address Blocker sunset.
Install and publish only the types you mean
A merchant publishes billing-address rules by installing AddressFence from apps.shopify.com/address-guard, turning on the billing job the listing describes, and publishing to checkout validation. The same listing covers require a street number — the Address Blocker rule that was not migrated. Test any address in the simulator before publishing, with one-click rollback.
- Open the AddressFence listing (
apps.shopify.com/address-guard) and install it. - Turn on billing-address rules (and only the extra types your policy needs). Target billing if that is the gap.
- Publish to checkout validation.
Confirm the live listing. AddressFence is checkout address validation, not legal advice.
What the PO Box comparison is not
The PO Box comparison explains shipping-rate hide, native Checkout Blocks shipping validation, and AddressFence billing validation. The comparison is not an instruction to block every PO Box, not a shipping-only how-to, not B2B purchase-order number validation, and not a fraud, AVS, or chargeback guarantee.
- Not an instruction to block every PO Box.
- Not a shipping-only how-to. If only ship-to format blocks are needed, native checkout validation may already cover the job.
- Not B2B purchase-order number validation. That job is B2B PO number required.
- Not a fraud, AVS, or chargeback guarantee. Not legal advice.
Can Shopify checkout already block a PO Box?
Yes, on shipping: since 17 June 2026, Checkout Blocks address validation is available to all merchants and can block a PO Box on the shipping address, while billing address is not covered. Shopify Help names PO box among the address types you can block, and states that billing fields are not validated. Hiding carrier rates for a PO Box ship-to is a different control, because rate hide removes a rate and does not attach a field error to billing. Native Shopify can block PO boxes on shipping. The remaining gap is billing and edge cases, not “Shopify cannot block PO boxes.”
Should I block every PO Box?
No: do not turn on every address type just because a shipping format list includes them, and leave PO Box shipping available when buyers legitimately receive parcels at a box. Do not copy locker, military, or diplomatic types onto billing unless that is the store policy; gift checkouts also break if shipping and billing are forced to match.
Where does AddressFence still differ from native shipping-rate hide and checkout validation?
Native checkout can block non-compliant shipping addresses for every merchant since 17 June 2026. AddressFence pages on momiji-space document billing-address rules — built-in checkout rules cannot target billing at all — and require a street number after Address Blocker sunset on 31 August 2026 (handle address-guard). Test any address in the simulator before publishing, with one-click rollback. Merchants should not block every PO Box.
Does hiding shipping rates stop a PO Box on the card billing address?
No: carrier rules and delivery customizations decide whether a rate is offered to a ship-to, and digital carts plus billing-different-from-shipping still collect a billing address. Rate hide does not validate billing fields and does not attach a checkout field error on a PO Box used only for the card.
Does the PO Box comparison guarantee fewer chargebacks?
No: the PO Box comparison does not guarantee fewer chargebacks, because rejecting an address pattern is not AVS, not a fraud guarantee, and not legal advice. False positives happen if a street line contains “PO Box” as extra text.
Related pages
- PO box blocker for the billing address — billing-address rules
- PO Box Blocker — AddressFence — live App Store listing
- Reviewer screencast
- B2B PO number required — purchase-order numbers, not PO Boxes
- Staff permissions audit checklist
- Shopify apps hub
- Tools
Not legal advice. Not a fraud or chargeback guarantee. Do not block every PO Box. Native shipping PO Box blocks do not validate billing. Sources: Shopify Changelog: Checkout Blocks address format validation · Help: address format validation · AddressFence on the App Store.