Which app you need for Shopify depends on which Shopify store subscription plan you have. Shopify Basic, Standard and Advanced plans do not have the functionality to customise the checkout in any way, so we have developed 2 apps that can be found in the Shopify App Store, one for Plus merchants and one for Basic, Standard and Advanced merchants.
Shopify Plus merchants
Since the launch of Shopify Plus Checkout Extensions, Shopify Plus merchants will benefit from our new Data Validation App for Shopify Plus Checkout Extensions.
The new app is quick and easy to install and gives you :
Full UK Postcode Lookup, Global Address Auto-Complete and Email Address Validation
Increased conversion with faster checkout
Accurate addresses worldwide with predictive address results for all our territories (The native solution in Shopify Plus from Google only covers 20 countries)
Shopify Basic, Standard & Advanced merchants
These Shopify plan levels do not include functionality to modify the checkout which means that address lookup within the checkout is currently only possible with their free Google Address Autocomplete, which covers only 20 countries.
Since 2021 we have offered an alternative Address Check app which provided a single corrected suggestion to inaccurate addresses in the store Order Confirmation and Thank You pages, however, new functionality released by Shopify has rendered this app obsolete.
You can read more about this here