All UK NHS Performers Lists require enhanced DBS checks for GP locums. Haven’t GP locums already had an enhanced DBS check? The enhanced Disclosure and Barring Service (DBS) check (previously known as the Criminal Records Bureau (CRB)) can be requested by a GP practice to help assure them that an independent contractor – in this case, a GP locum – does not have a criminal record that would otherwise bar them from working as a GP in their practice.