If the work that you did for the two companies was similar in nature, then you can report them both on a single Schedule C. For example, if you did web design for two different companies you would use only one Schedule C.
When you are entering the basic information on the Schedule C, the EIN and address it is asking for is the EIN and address for your business, not the companies who paid you for the self-employment work that you performed. If you received a Form 1099-MISC from the companies who paid you, then their information is reported on the Form 1099-MISC, but not directly on the Schedule C. If you do not have an EIN for your Schedule C business, then leave it blank -- it is not required for everyone who files a Schedule C.
