keyholder
From Longman Dictionary of Contemporary Englishkeyholderkey‧hold‧er /ˈkiːˌhəʊldə $ -ˌhoʊldər/ noun [countable] someone who is officially responsible for keeping the key to an office building, factory etcFrom Longman Business Dictionarykeyholderkey‧hold‧er /ˈkiːˌhəʊldə-ˌhoʊldər/ noun [countable] someone who officially has the key to a particular house, factory, office etcThe police have a list of keyholders to the building, with their home telephone numbers.