This document is a guide that outlines the seven hidden costs associated with public purchasing. It explains how failing to manage vendors, bids, and contracts online can lead to significant financial impacts that are not immediately visible on invoices. The guide details various cost factors including staff distractions caused by constant vendor communications, the inefficiencies of data entry and errors, and the challenges of maintaining up-to-date vendor information. Additionally, it discusses the repercussions of insufficient vendor responses, such as the need for rebids, which incur further costs. The document also highlights how a lack of competition among vendors can lead to higher prices and the potential for vendor complaints and contested bids. Furthermore, it addresses the issue of uninsured vendors and the difficulties in managing their documentation. The guide concludes by recommending the use of effective vendor and contract management systems to mitigate these hidden costs.