Employment history verification is essential for assessing a candidate's reliability and integrity. This article outlines best practices for verifying at least three years of a candidate's employment or activity history. We explore methods for confirming past employment, handling gaps in employment, and verifying periods of self-employment or education. The article also addresses the challenges of international employment verification and how to overcome them. By employing meticulous verification processes, Checkback helps organizations mitigate risks associated with fraudulent employment claims and ensures that candidates meet the stringent requirements of BPSS clearance.