Prior to your mailing being sent to a Mail House, please send a Bulk Mail Request Form to General Accounting detailing all requested information in detail. By signing in or creating an account, some fields will auto-populate with your information.Join the Clark Business Community! Clark requires suppliers to receive Purchase Orders and submit Invoices electronically either via Coupa Supplier Portal (CSP) and cXML Transmission. How do I fill this out? A purchase order (PO)is a form of a contract and is a legal document used to place order for goods or services with a vendor. Learn how to conduct business with us through Coupa, Clark's procure-to-pay system for purchase orders, invoice processing, and payments. The Tax Collector's Office is responsible for collecting Real Estate taxes for all properties in Clark Township. Simple 30 page fill-in-the-blanks business plan template. Easy to complete and SBA ready for approval.