The OpenCart 1.5 Administrator Dashboard allows you to specify your customer into groups that you can use for organization purposes. The following tutorial will guide in creating groups for your customers in the Sales menu.

How to Add Customer Groups in OpenCart 1.5 Administration Dashboard

1. Login to the Administration Dashboard as an Administrator
2. Hover over the menu bar where it says SALES and then click on CUSTOMERS in the drop-down menu
3. Another menu will appear and you can select the CUSTOMER GROUP  to ADD an a new group name.  You will get list as shown below:
   
   
   
4. Click on INSERT to add a new group name.
5. Type in a new group name
6. Select SAVE in the top right hand corner to save the new group name
   
   

You can see the new group added above as "test group".  Use the customer groups to help organize your customers.  You can assign a customer group as a default group in the Systems Preferences under Options Customer group.  You can find more information on that subject here: Changing the Default Customer Group.