Plugin · no coding required
Postcode check and address validation for OpenCart 4
With the OpenCart 4 extension by Postcode Checkout, customers only enter their postcode and house number in your checkout. The street and city are filled in automatically, so every address is correct.
Version 1.0.7 · updated on 10-08-2026 · developed by Postcode Checkout
Delivery address
Street and city filled in automatically
Why address validation in your OpenCart webshop?
No typos in addresses
The street and city come from the official address data, not from your customer's keyboard. That makes most address errors disappear.
Faster checkout
Fewer fields to fill in makes the checkout shorter. Customers who order on their phone notice that the most.
Happier customers
An order that arrives on time and at the right address leads to better reviews and customers who come back.
What do you need?
The OpenCart 4 extension is developed and maintained by our partner Postcode Checkout. The address data comes from Nederland Postcode API. That is why you need a subscription with both.
Nederland Postcode API
For the address data
- 10+ million addresses
- From just €59.99 per year
- Unlimited websites and webshops
- Test for free with a test API key
Postcode Checkout
For the OpenCart 4 extension
- Ready-made OpenCart 4 extension
- Updates and installation support
- License per number of websites
- Free trial period
Frequently asked questions about the OpenCart 4 extension
- Which OpenCart versions are supported?
- The extension is made for OpenCart 4. You can find exactly which versions are supported on the Postcode Checkout website.
- What does the OpenCart 4 extension cost?
- You pay for two things: a subscription at Nederland Postcode API for the address data, from €59.99 per year for an unlimited number of websites, and a license at Postcode Checkout for the OpenCart 4 extension itself. You can find the current license prices on the Postcode Checkout website.
- Can I test the OpenCart 4 extension for free?
- Yes. With a free account at Nederland Postcode API you get a test API key that works for postcodes starting with 1012, 1015 or 1118. Postcode Checkout offers a free trial period for the OpenCart 4 extension. That way you can test everything before you pay.
- Can I use one subscription for multiple websites?
- Your Nederland Postcode API subscription covers an unlimited number of websites and webshops, including client projects. The Postcode Checkout license depends on the number of websites you install the OpenCart 4 extension on.
- What happens when I reach my limit?
- You receive an email at 80%, 90% and 100% of your monthly limit. At 100%, new requests are rejected until the start of next month. You never pay extra for requests above your limit.
Ready to add address validation?
Create a free account, test with your test API key and only pay when you go live.
