If your business is a sole proprietorship (Sch. C) or your business is conducted as a one-member LLC, you don't need an EIN issued by the IRS. You instead use your social security number. The bank should be able to accept your social security in this situation. If you are "making up" a business to get the miles you won't want to get an EIN. Once the IRS issues an EIN, they expect future tax returns. The IRS won't expect anything beyond your normal Form 1040 if you use your social security number to register a business checking account. The IRS won't even know about it since the bank will issue any 1099s in your name and social security number.