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modlet: Block PO Box & Lockers
- by modlet
- Free plan available. Free trial available.
- by modlet
- Free plan available. Free trial available.
Stop paying carrier return fees for undeliverable PO Box and locker addresses with reliable, global checkout blocking.
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About the modlet: Block PO Box & Lockers
This app blocks PO boxes and lockers at checkout to prevent failed deliveries and expensive carrier return fees. Built directly into Shopify Checkout, it physically stops customers from completing orders to restricted addresses, ensuring 100% reliable blocking that can't be bypassed.
The app protects your shipping margins with global PO box blocking and includes a built-in address simulator to test your rules safely. Pro features let you create custom error messages for your brand and local languages, plus set specific exception rules for different shipping methods, regions, or products.
Built by a veteran cloud architect with efficient infrastructure, the app offers a generous free tier to help new stores grow. Upgrade to Pro as your order volume increases or when you need granular shipping rules and customization options.
Launched: March 9, 2026
Key features
- Block PO Boxes and lockers worldwide to stop failed deliveries.
- Secure checkout blocking that buyers cannot bypass or work around.
- Test your blocking rules safely using the built-in address simulator.
- Pro: Create custom error messages to match your brand and local languages.
- Pro: Set specific exception rules for shipping methods, regions, or products.
Integrations with:
- Checkout
Category:
Pricing of modlet: Block PO Box & Lockers
Free
Free
- Block PO Boxes globally (Instant setup)
- Up to 250 Store Orders per Month
- Native & Secure Checkout Validation
- Address Simulator & Testing Tool
Pro
$10.99 / month
or $99.99/year and save 24%
- Unlimited Orders & Address Validations
- Custom Error Messages & Translations
- Shipping Method Filtering
- Product Exemptions
- Country & Region Whitelisting
- Granular Pattern Rules
- VIP Customer Tag Exemptions
Enterprise
$99.99 / month
or $999.99/year and save 17%
- White-Glove Setup & Dedicated Onboarding
- On-Demand Custom Data Exports & Reports
- Priority Custom Feature Development
- Dedicated Technical Account Manager
- 1-on-1 Workflow & Strategy Configuration
- Guaranteed Custom SLA & Compliance Help
