FP1 - Postcode Shipping Guard
Keep your existing Shopify shipping zones — and block restricted Postcode/Postal/ZIP codes inside those zones at checkout with simple rules. Optionally show a warning in the cart before checkout to set expectations early.
Best for: stores that ship broadly but need postcode exceptions. Not for: replacing Shopify shipping zone configuration.
$5.99/month after 14-day free trial • billed by Shopify • 30-day first-charge satisfaction guarantee
What it does
- Keep your existing Shopify shipping zones — PSG blocks restricted Postcode/Postal/ZIP codes inside those allowed zones.
- When a customer enters a Postcode/Postal/ZIP code at checkout, the app compares it to your rules.
- If a match is found, checkout is blocked for that destination with a clear message.
- Supports both exact matches (full code) and prefix ranges (a group of codes that start the same way).
- Optionally show a short notice in the cart (if you add the theme block) to set expectations before checkout.
How it works
- Your Shopify shipping zones define where you ship in general.
- In Shopify Admin, you add one or more PSG rules (your restricted code list) to create exceptions inside those zones.
- At checkout, the customer’s entered Postcode/Postal/ZIP code is evaluated against your rules.
- If the code is blocked, checkout shows no delivery options for that destination, preventing completion until the customer changes the address.
- If you enable the optional cart notice, the cart can show a short warning before the customer reaches checkout.
How to write rules
- Exact match: block a full code (for example
SW1A 1AAor94105). - Prefix range: block a group of codes that start the same way (for example
SW1A*,941*, orM4B*). - Shorter prefix = larger area:
SW1A*is narrower thanSW1*.SW*blocks a much larger area. - Spaces are ignored (for example
SW1A 1AAmatchesSW1A1AA, andM4B 1B3matchesM4B1B3).
Country filter (optional — only for multi-country stores)
- Leave this as Not set (recommended) if you sell in one country. Use it only for multi-country shipping, so the same Postcode/Postal/ZIP code doesn’t get blocked in the wrong country.
- If needed, use a two-letter country code (US, CA, GB, AU, etc). If you don’t know it, select “Other” and enter the country code or a common country name.
Key benefits
- Block restricted pockets inside the regions you already allow in Shopify shipping zones.
- Stops orders that you can’t service from reaching fulfillment and creating support tickets.
- Prevents accidental sales to restricted Postcode/Postal/ZIP codes (based on your rules).
- No-code setup — add and adjust rules anytime.
- Optional cart notice helps reduce surprise at checkout.
FAQ
Does this change my theme?
No theme changes are required for checkout blocking. The optional cart notice only appears if you add the app section to your cart template.
What Postcode/Postal/ZIP formats are supported?
You can block a full code, or block a group by using a prefix with an asterisk at the end (like
SW1A*, 941*, M4B*, 2000*, and many others).
Shorter prefixes block larger areas.
Do you store customer addresses?
No. The app evaluates the customer’s Postcode/Postal/ZIP code only to apply your rules. Your rule settings are stored for your shop.
How do I get help writing rules?
Email [email protected] with your shop domain and a few examples of codes to block. We’ll help validate the rules.
How does billing work?
Uses Shopify Billing with a 14-day free trial, then $5.99/month. You’ll be asked to approve billing to enable checkout rule enforcement. Charges begin after the trial unless you uninstall or cancel before that date. Uninstalling stops future renewals. Shopify doesn’t automatically prorate unused time in the current billing period. If the app is not a fit, email us within 30 days of your first paid charge and we’ll refund that first month.