Codes are used as keys to access records and so, once set, cannot normally be changed. However, if a code is incorrect, select this view from the Tools section of Administration. This is only possible if permitted through your Login Profile.

Select the Entity Type for which the code is to be changed and the Old Code from those listed. Then enter the New Code to be used instead and click   to make the change. The new code must be unique; you cannot convert a code to merge it with an existing one. All references to the code are changed.