First decide on a business structure Connecticut as a Sole Proprietor, LLC/Corp, or Partnership.

Selling/Leasing or if wanting to buy or sell Connecticut merchandise, food, equipment wholesale requires a Seller's Permit.

All CT Businesses Using a DBA doing business as name need a DBA Fictitious Business Name

Hiring CT Workers Requires a Federal EIN and a State Tax Number EIN

You must obtain a  Seller's permit  from the Department of Revenue Services if  you intend to engage in any of the following activities in Connecticut:

      

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  Sale, rental, or lease of goods;
      

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  Sale of a taxable service; or
      

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  Operating a hotel, motel, or lodging house.

You must obtain a  Seller's permit  before making any in state sales. If you are  purchasing an existing business, you may not use the  Seller's permit  issued to  the previous owner. You are required to obtain a new  Seller's permit  if you  will have more than a single place of business, you must obtain and display a    Seller's permit  for each location.

The requirement to obtain a permit applies to individuals, corporations,  partnerships, and all other business entities that will make sales in this  state, regardless of the number of sales that will be made or the amount of tax  that will be collected. These rules do not apply to casual or isolated sales,  which are in-frequent sales of a non-recurring nature made by a person not engaged  in the business of selling tangible personal property or taxable services.   Manufacturers and wholesalers, as well as retailers, must obtain a permit.

As a seller, you are responsible to collect sales and use taxes and you are  liable for their payment whether or not you collect them as required from your  customers. You must file returns and pay the full amount of tax due to the dept  of revenue in CT.   Failure to obtain a tax permit will result in a fine of not more than $500 or  imprisonment of not more than three months, or both, for each offense.