You might need a tax exemption permit from your state to avoid paying taxes on the stuff you buy and some states require the collection of sales tax on sales within your state. Talk to your local office for your state s Dept. of the Treasurer for an accurate answer.
You do not need a license to buy things from wholesalers online or on land. And I do not think you need any license to sell things on eBay either because most eBay sellers are amateur. Many of them are just one time sellers. To check for sure, contact your local City Hall.If you are a drop shipper (products ship directly to your customers from suppliers), you do not have much to worry about. However, if you import products from aboard, you may have to apply for a importer s account number as well as GST number (in Canada). You can have it done at the Custom.
If this is a business then I d say yes you need a proper registered and lic d business. The govts in many jurisdictions are cracking down on e-bay and other online sales so as to get their share of sales taxes and income taxes. There are publications and online info available from many govt tax depts that specifiy who needs to report their sales etc and pay what taxes and of course they also have lists of what products are exempt from their taxes.
