QAS is a third party address verification service which gets the full address from a given postcode and street. You can find more details in their website
http://www.qas.co.uk/products/capture-name-and-address-data/pro.htm
We had to do integration for Australian Post Codes and Street Addresses. So, we were given the web service by QAS which we needed to plug in to AX
Integration with Dynamics AX
a. Consume the QAS Web Service by going through Tools > Development Tools > Application Integration Framework > Add Service Reference
b. Once the Service Reference is added, write a class to instantiate the proxy and pass the zip code and street name
c. Here is a sample code snippet which does the call to QAS and retreives the full address
We are calling this class from different forms like Customers, Sales Orders, CRM wherever we need to validate address with QAS
