Client requests for background checks

A fellow member receives requests from clients to have background checks performed on their employees before they perform work on engagements for those clients. The scope of the background checks may differ from one client to the next, as do the clients' decisions regarding which employees are permitted to perform work for them. Their Security team would like to create a document (i.e., a grid or matrix) that can be provided by the company to clients showing the background checks that they already do on employees at the time of hire, as well as the mitigating factors they consider to avoid having to do multiple background checks on the same individuals.

The member is interested in any best practices or information regarding a matrix used for background checks. Please answer the questions below.