How to Become a Vendor

Washtenaw County utilizes a self-service portal that allows prospective vendors to create an online account and apply to be a vendor. The same portal allows vendors to view purchase orders and payment information. Please read our instructions for creating an account. The prospective vendor must fill out the self-service application completely and attach a W-9. Please pay attention to the instructions included in the documentation.

Modifying Information

Even though the self-service portal allows a business name change, a letter noting the change must be sent to Washtenaw County Accounts Payable on company letterhead. The letter must be signed by a principal of the company. 

Washtenaw County Accounts Payable
PO Box 8645
220 North Main St
Ann Arbor, MI 48107-8645

More Information

Learn about Doing Business with Washtenaw County, by reading our brochure (PDF).