Registered office is a place which is registered with the ROC at the time or registration and subsequent changes by way of Form 18. However, Word Corporate office is not defined anywhare in the Companies Act, 1956. You can have more than one corporate office in different city of state, but you have only one registered office in which state where the company is registered. One can take stand that any place which is not registered office as per act, where majority of the business of the company is undertaken, can be treated as Corporate Office.