For me, I never made bows as a hobby. I wanted my own business right from the start. (I used to make and sell them when I was younger.) As soon as I decided that, I went online and applied for an EIN (Employer ID Number) which I am pretty sure is the same as a tax ID. My main reason was so that I could purchase large quantities of supplies at wholesale prices. To start up, I used extra money that I had to stock up on ribbons, clips and headbands. I still have to make that money back though! Unfortunately, I have not had much time lately to devote to my business or to promote it correctly.
Definitely get the tax id number. It costs nothing to do so.