RE: Navision customer creation
You might have a need to divide them either by legislation requirements or by your own internal business requirements.
E.g., you would perhaps need to define different posting groups, as according to your local legislation there might be differences in treating customers as companies and physical persons.
For internal business requirements, you can divide them by e.g. different series numbers as offered by Amol, or use some standard fields to make this distinction. Also, for many cases you might not need to create a new customer card for each particular physical person. As they do e.g. in retail, you can create one unified card for physical person and book all transactions with all physical persons to that unifying card.