To access a bid please go to Vendor Portal and click the "Nassau County Procurement". Welcome to the Online Vendor Bid Site for suppliers and bidders interested in bidding opportunities for the commodities services and technology contracts.We have also attached Bid Specifications, a Bid Response Form and certain Appendices. SEALED RFP: All RFP sheets, requested documents and this form shall be executed and submitted in a sealed envelope. Bidders are required to fill out the following bid sheet: 11.