The geo code button can be used on several entities like Accounts, Contacts, Work Orders. By clicking this button a dialog/ pop-up appears and bing tries to calculate the latitude and longitude from Microsoft standard fields. Currently there is no possibility to extend this dialog for custom fields. (E.g. some customer are using 2 fields for the address1_line1 (street and house number(custom field))) This means that the custom fields are not included in the geo data calculation and either no or incorrect geo data are found.
Idea: Open this dialog for custom address fields.