A 1040 is the tax return form you prepare here to send to the IRS. If you start entering data in this software you are preparing a Form 1040. Please look at it so you will know what you are sending to the IRS:
PREVIEW 1040
If you have self-employment income you need to use online Premium software or any version of the desktop download so that you can prepare a Schedule C for your business expenses.
Yes, you can file Form 1040 through TurboTax if you have an LLC. If you have a Single Member LLC (you are the only member) and you did not elect to be treated as an S-Corp, then the IRS considers your LLC a "Disregarded Entity". It doesn't change anything about how you file your tax return. If you have a business, you are self-employed and you file your business income and expenses on Schedule C as a part of your personal tax return (Form 1040). For more information, see the following IRS webpage: Single member limited liability companies
You may be mixed up.
A form 1040 is just your regular tax return that you always file.
If you formed a single member LLC, that is considered a "disregarded entity". You report your income and expenses on schedule C, which is attached to your regular tax return. Schedule C calculates your taxable income or loss, and that information flows to the rest of your tax return (form 1040) where it is combined with any other income, and your personal deductions and credits, to calculate your final tax.
However, if the LLC has more than one member, you must file a form 1065 partnership return. This is a different tax return and requires a different business tax program. The 1065 lists income and expenses, and the profit or loss is passed on to each partner using a K-1 statement, that is added to each partner's personal tax return. (There are special rules if the only other member is your spouse and you live in a community property state.)