| 1-Member LLC's without Employees
The IRS has stated that " you will not need a separate Federal Tax ID number for an LLC of which you are the sole owner of the LLC and the LLC has no employees."
1-Member LLC with Employees
However, if you are the sole owner of the LLC and the LLC has employees, the IRS has specifically stated "you will need to get a separate Federal Tax ID number, if you choose to have the LLC report and pay employment taxes with respect to employees of the LLC."
I would always recommend a separate EIN, where possible!
2-Member LLC-Requirements
Now, If you are not the sole owner of the LLC by that I mean there are more than 1 member's,the IRS has specificall stated "you will need a separate Federal Tax ID number for the LLC". | 
