That is fine with me.. I do not want to charge you unless you are completely satisfied.
My main concern is how IN DOR find out about your selling activity.
I suspect that you mistakenly registered with them and now they are sending you a bill.
Or any of your buyers reported that they paid sales tax to you.
Or if you deliver merchandise using your own transportation - that might be considered as business activity.
That what you need to clarify.
Please have this for your reference - http://www.in.gov/dor/files/bt-1-annotated.pdf - and see references to code sections.
Retail Sales Tax Account: $25.00 Nonrefundable Registration Fee or Out-of-State Use Tax Account: No Fee retail Sales Tax is applicable whenever selling activities are conducted in Indiana; whenever a business location, warehouse, distribution center exists; or whenever employees solicit or take orders for your products in Indiana (this includes wholesalers). Upon registration for retail sales tax, the Department will issue a Registered Retail Merchants Certificate.
The registration fee of $25.00 is a nonrefundable processing fee and must be remitted with this application when registering for sales tax. Each business location, including manufacturers, per 45 IAC 2.2-8-7, must have a separate Registered Retail Merchants Certificate. A change of ownership
requires a new application to be filed along with the $25.00 fee. For example: A sole proprietor changing to a partnership or corporation is a change of ownership. Retail sales tax rate is 5% (.05).
Out-of-State Use Tax is a voluntary registration available to out-of-state businesses not meeting the conditions listed for retail sales tax. Upon registration for out-of-state use tax, the Department will issue an Out-of- State Use Tax Collection and Remittance Permit. This permit authorizes your business to collect Indiana Use Tax on sales shipped into Indiana. There is no fee associated with this registration.