If your dept. It has a lot of employee info (multiple id types/numbers, emergency contact info, etc.), and you can add additional custom fields to employee profiles. These are called "Custom Employee Attributes".
 

Create the Custom Fields

To begin, go here (Admin Tab -> Settings -> Site Settings).

• The first option on the page you arrive at is "Custom Employee Attributes", with a link next to it that allows you to View/Edit these attributes. Click that link that says Modify.

• This new page will likely be blank for you right now, as we don't have any custom fields yet, but as we add them, they will be listed here.
   
• Click the blue "+ Create Custom Employee Attribute" button to create a new field.

• Now, all you have to do is name the field you want to add (I chose "Payroll #") and select an attribute type, which can be either plain ol' text, a date, or a dedicated Payroll ID format.
   
• When you have chosen these, click the blue "Create" button. 

That's it! Employee profiles will now have a new field at the bottom called "Payroll #" that you can fill out for each person. You can add additional fields as you see fit.  

NOTE
These custom fields are currently only available for viewing/use on custom exports and the profile itself.