Are you the sole proprietor of both businesses?
If so then do the following:
First, you can do both businesses under one account, because the two businesses will be reported on two Schedule Cs which will be part of your one 1040 tax return.
To enter the businesses in TurboTax
Self-Employed, go to Business->Business Income
and Expenses. Click on the Add a Business button and begin the interview on the information, income, and expenses of your first business.
When you are finished with this, return to Business->Business Income
and Expenses and click on the Add a Business button again to begin the interview for the second business.
Since the income and expense items are reported within each business, this
will keep the income and expense items from being commingled between the
businesses. NOTE: this means that you will not enter thing related to a business (like a 1099-MISC) in your personal info, but under the business that this form belongs to.
Note that a business does not have to have an EIN (for example, if you have
no employees), the business without an EIN will default to your Social Security
Number.
The result of the interviews for the two businesses will be two Schedule Cs
on your 1040.
