The web services are implemented using Microsoft WCF and uses basic http binding for full interoperability. All communication with Collector services is encrypted using https. The Payment service is published through a web services description language (WSDL) file.
The order of the parameters are of importance. Please note the order presented in each request.
The parameter CountryCode must always be supplied, StoreId is optional as long as only one shop per country is used. Partners with multiple shops in the same country are required to submit the StoreId in each request.
In all requests you can also send in a CorrelationId, which could be used to verify that the response is from the "correct" request.