King Checkout Validation

King Checkout Validation

Pricing
Free plan available. Free trial available.
Highlights
Use directly in Shopify admin
Rating
5.0 (8)
Developer
Gordon Kihn

Block checkout errors and enforce checkout validation with real-time address validation

Our app blocks invalid checkouts by detecting missing house/apartment numbers, validating VAT/tax ID formats, and filtering non-Latin characters. Customize address validator rules for field lengths, keyword restrictions, or regex patterns—adapting checks to cart value, product types, and shipping zones. Streamline compliance, reduce return rates, and prevent failed deliveries through automated error blocking—all managed in one dashboard.

Our app blocks invalid checkouts by detecting missing house/apartment numbers, validating VAT/tax ID formats, and filtering non-Latin characters. Customize address validator rules for field lengths, keyword restrictions, or regex patterns—adapting checks to cart value, product types, and shipping zones. Streamline compliance, reduce return rates, and prevent failed deliveries through automated error blocking—all managed in one dashboard. more
  • Block invalid checkouts with real-time validation checks
  • Auto-detect missing house/apartment numbers, block Post office (PO) Box address
  • Validate fields base on keywords and regular express
  • Block non-Latin chars & enforce field limits
  • Customize validation rules based on combinations of order amount, weight, etc
Highlights
Use directly in Shopify admin

Languages

English

Works with

Pricing

Free

Free

  • Free of charge for development store
  • Creating rules in test status

Basic

$4.99 / month

  • Live chat, email support
  • Missing house number, apartment, suite
  • Missing VAT number Checker
  • Prevent Post office (PO) Boxes

7-day free trial

Premium

$9.99 / month

  • All from "BASIC"
  • Non-Latin Detect
  • Field length Rule
  • Matching keywords Rule
  • Regex Express Rule
  • Customized Combination Validation Rule

7-day free trial

All charges are billed in USD. Recurring and usage-based charges are billed every 30 days.

Reviews (8)

Overall rating
5
Counts per rating level
  • 88% of ratings are 5 stars
  • 13% of ratings are 4 stars
  • 0% of ratings are 3 stars
  • 0% of ratings are 2 stars
  • 0% of ratings are 1 stars
September 12, 2025

This app really saved us. We have an integration with SAP, and some fields have character limits that can’t be changed. This app solved that issue, and we also used it to block sending orders to certain islands via ZIP code rules — which works perfectly. I highly recommend this app. We’re running it on eight stores now.

Gorilla Sports
Germany
12 months using the app
July 25, 2025

This is a fantastic product and the developer is extremely responsive and helpful! Great app!

Stur Drinks
United States
7 months using the app
February 10, 2025

Created a new functionality, the day after reaching out on chat for advise on how to setup a feature, and testing the initial solution.

A.Kjærbede
Denmark
3 days using the app

Support

App support provided by Gordon Kihn.

Developer

Gordon Kihn

Baoan district, Shenzhen, GD, 510000, CN

Launched

March 15, 2024

Data access

This app needs access to the following data to work on your store. Learn why in the developer's privacy policy .

View personal data:

Store owner

  • Store owner

    Name, email address, phone number, physical address

View and edit store data:

Products, Shopify Functions

  • View products

    Products or collections

  • Edit Shopify Functions

    Cart and checkout validations

  • View other data

    Locales

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