I generally do not bring up tax issues. Not being an accountant, I avoid getting into the nitty-gritty of tax law. This post still avoids the details of tax law for more general. Indiana's Department of Revenue has the following information for new businesses in Indiana at Register a Business.
If you are starting a new business in Indiana, you may need to register with the Indiana Department of Revenue (IDOR). Registration is required if you will have employees, intend to engage in selling (retail or wholesale) and/or renting/leasing tangible personal property, etc..
If you indicate on your Business Tax Application (BT-1), that you will be collecting Indiana Gross Retail Sales Tax you will be issued a Registered Retail Merchants Certificate (RRMC). A RRMC must be displayed at each location you intend to collect Indiana Sales Tax and/or issue and receive exemption certificates.
A company that has no employees and simply provides a service may not need to register. If you are unsure, please contact the Department for additional information.
There is separate information for Independent Contractors doing business in Indiana. Please review this information for things you need to be aware of.