There is not a way to delete or remove unused contact data fields, but there is a way for them to become "hidden" and not populate when segmenting or exporting contact data information.
- Go to the Contacts dashboard
- Click on 'Configuration' (left menu)
- Click on the 'Configure Fields' tile
- Hover over whichever field you do not want to visibly see within the UI and click on 'Edit' button (right side). The Edit Field page will open.
- Locate and check the box for 'Hide this field from account admins'.
- Click 'Save' (top right).
- Following the steps above will hide the field from selection menus when creating segments, merging fields into content, and from any operation that allows the export of contact data. For example, if you export contacts from the Contacts module, the hidden field will not populate from the list of fields to export.
- Should you ever need to have a hidden field become visible, go back through these steps to uncheck the hidden box.