Supplier sub types allows you to drilldown your Supplier Types further – E.g. Type Meat & Poultry > Sub Type = Chicken. So, the Sub type is Chicken. Further categorising & classifying your supplier list.
Step 1: Go to Supplier Manger, then select Admin, General Admin & Optional fields on the left
Step 2: Turn on if you want it to be active
Step 3: Select menu key
Step 4: Select Add New Categories. Then add the Category Name & select the Parent Category that it belongs too (that you setup in Company Supplier Types)
Step 5: Once done select Add/Update Categories. Repeat steps to add more categories
Step 6: Your categories will end up looking like this. At any stage if you need to edit follow the steps above.
Step 7: Once done there select Save Settings