Background verification is the confirmation, before or shortly after joining, that what a candidate told you about themselves is true: where they actually worked and how they left, what they studied, where they live, who they are, and whether there is a court record. Use it on every hire who will handle money, data, customers or people, and on any hire whose CV carries a gap you could not close in the interview.
The value of a BGV report is entirely in its honesty about limits. Employers shut down, HR desks stop replying, universities take as long as they take, and a name-based court search in India is not the same thing as a clean record. A report that quietly rounds those up to 'clear' is worse than no report at all, because you then make a decision believing something was checked when it was not.
So we run the checks in parallel rather than in sequence, chase the ones that stall, and report each component separately with its own status: verified, discrepant, or insufficient with what was attempted. You get a decision to make, not a verdict handed to you.