Yes, it is necessary but don't know where you are located. If you are invoicing clients then you have to collect, say a goods and services tax and in order to report it to the government on a quarterly basis you have to have an ID.

is it necessary for me to get a tax ID, I am the only employee in my startup company?Hello p:

If you're buying goods for resale, you'll need one so that you don't pay sales tax. If you're NOT buying goods for resale, then you don't need one.

excon

Is it a sole proprietorship (no corporation or LLC)? You can use your Social Security number instead.