Plugin · no coding required
Postcode check and address validation for CS-Cart 4
With the CS-Cart 4 add-on by Postcode Checkout, customers only enter their postcode and house number in your checkout. The street and city are filled in automatically with address data from Nederland Postcode API.
Version 3.1.2 · updated on 17-09-2026 · developed by Postcode Checkout
Delivery address
Street and city filled in automatically
Why address validation in your CS-Cart webshop?
Correct delivery addresses
Every address is checked before the order comes in. That prevents parcels coming back because a house number or street name was wrong.
Shorter checkout
Customers only type their postcode and house number. The rest is filled in, which makes paying faster.
Less manual work
You no longer need to check or correct addresses by hand before you ship an order.
What do you need?
The CS-Cart 4 add-on 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 CS-Cart 4 add-on
- Ready-made CS-Cart 4 add-on
- Updates and installation support
- License per number of websites
- Free trial period
Frequently asked questions about the CS-Cart 4 add-on
- Which CS-Cart versions are supported?
- The add-on is made for CS-Cart 4. You can find exactly which versions are supported on the Postcode Checkout website.
- What does the CS-Cart 4 add-on 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 CS-Cart 4 add-on itself. You can find the current license prices on the Postcode Checkout website.
- Can I test the CS-Cart 4 add-on 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 CS-Cart 4 add-on. 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 CS-Cart 4 add-on 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.
