1. Generally you need a Fed tax id, if you have employees, and you need to separate
yourself from the company for tax purposes - however, you could do your taxes under your social security if you don't have employees.
· However, the question is whether you want to do business under your social security #.
· If you do, all of your personal assets are subject to civil suits, and creditors.
· In addition, you can…YES you can build a separate credit line with a secured or unsecured business credit card or by obtaining a loan in the federal tax id. So long as you make it clear in the contracts you enter into, your personal assets are not completely at stake, because if you have a fed Tax Id (EIN), it is additional evidence that the party to the contract was dealing with a business and not an individual. – however, keep in mind that incorporation is the organization that really shields your assets and protects you from civil liability so long as you follow the corporate formalities.
2. Do I need a State Tax ID? See "1" above: you need it if you pay employee(s) more than $100 per year.
3. You need a seller's permit in California if you sell any type of products – YOU GET tax free purchases for ITEMS YOU BUY to resell.