Your list of suppliers can be managed from the Suppliers under Inventory in the side bar. You will only see the Suppliers option if your login account is an "administrator" role user. 

By clicking Supplier, this will provide a list of suppliers that have been defined on your account.

You can add new supplier information by clicking the Add button.

You can edit supplier information by clicking the spyglass button to the right of the suppliers in the list for your to edit or update your account number. This will display the supplier details and a list of all past orders for this supplier.

If making changes, please ensure to click SAVE.