How do I create a new Customer Business Type?

First, you will navigate to Admin Tools > Customer & Vendor Settings > Business Type Entry.

This will show you all current Business Types. To add a new one, click Add Line. Enter the name of the Business Type and add a brief description of that entry. Don't forget to hit Save when you're done!

Click Yes.

See related:

How to create a customer.

How to assign a business type to a customer.