No, you don't usually need an EIN if you're self- employed. These are the exceptions:

 If you’re a sole proprietor, you must have an EIN to:

• hire employees
• have a Keogh or Solo 401(k) retirement plan,
• buy or inherit an existing business that you operate as a sole proprietorship
• incorporate or form a partnership or limited liability company, or
• file for bankruptcy.

Also, some banks require you to have an EIN before they’ll set up a bank account for your business.