Solution ID enables software vendors to uniquely track the transactions submitted from their application to Authorize.net.
Unlike your merchant referrals, which are tied only to your Affiliate ID, Solution ID identifies the application creating a transaction for every merchant using your software regardless of who sold the application, gateway or merchant account.
Partners can create and manage Solution ID within the Partner interface, and include it in transaction request API calls.
Important Note: Now Partners can setup multiple Solution IDs that represent their platforms/products/software versions.
Currently the Authorize.net Affiliate Team exclusively sends reports until Partner Interface reports are in place: