There are few positions that merit a hiring background check more than ones directly involving the financial transactions of a company. Even if it costs a lot of money, it is absolutely money well spent.
As that last suggests, however, only certain roles are eligible for the checks, those being primarily roles that involve working with children or vulnerable adults, though the full list [0] is quite interesting.
[0] https://www.gov.uk/government/uploads/system/uploads/attachm...