From Longman Dictionary of Contemporary Englishhead officeˌhead ˈoffice noun BBO[countable] the main office of a company
Examples from the Corpus
head office• By Monday, he was back at head office orchestrating the move.• Or you can reach us at head office on Darlington 381313.• But there were far too few new faces, and far too many head office honchos.• The protocol at Ingard House was far more elaborate than at the head office of the bank.• These offshore branches can not close or fail while the head office remains open.From Longman Business Dictionaryhead officeˌhead ˈoffice (also main office)1[countable, uncountable] the main office of a companyThere is a customer liaison department at head office.New York used to house the main offices of hundreds of top companies.2[uncountable] the managers who work at the main office of a companyMost of the important decisions are made by head office. → office 