You should only register as a vendor if you have a business relationship with Fulton County Government (eg, being awarded a contract, purchase order, etc.). You must accept the terms of this agreement in order to apply as a vendor with COSF.Welcome Vendors and Thank you for your interest. To ensure your attendance as a vendor, please complete and return this form,. How do I fill this out? Com or call 917-364-5648. 2024, all vendors must be "Eligible for EFT" in the Vendor Self Service System. All items bid must be new. Provision within any standard form contract of the vendor. 2. Bidders are asked to completely and legibly fill out the return address portion of the bid envelope.