Provide a completed Sole Source Justification Form, which can be found in. Electronic Procurement Software in the Showcased Services area.How Do I Contact Purchasing? Register to receive notifications of upcoming bids in vendor's respective fields. Complete and submit bids online. Bystep guide to understanding the bidding process, along with tips on submitting a successful bid. INSTRUCTIONS: Bidders MUST fill out this form as part of the bidding process and attach to your bid response to Jefferson County, Missouri.