Self-employed individual

Self-employed individuals generally must pay self-employment tax (SE tax) as well as income tax. SE tax is a Social Security and Medicare tax primarily for individuals who work for themselves. It is similar to the Social Security and Medicare taxes withheld from the pay of most wage earners.

Before you can determine if you are subject to self-employment tax and income tax, you must figure your net profit or net loss from your business. You do this by subtracting your business expenses from your business income. If your expenses are less than your income, the difference is net profit and becomes part of your income on page 1 of Form 1040. If your expenses are more than your income, the difference is a net loss. You usually can deduct your loss from gross income on page 1 of Form 1040. But in some situations your loss is limited.  (See Pub. 334, Tax Guide for Small Business (For Individuals Who Use Schedule C or C-EZ) for more information.)

You have to file an income tax return if your net earnings from self-employment were $400 or more. If your net earnings from self-employment were less than $400, you still have to file an income tax return if you meet any other filing requirement listed in the Form 1040 instructions.

Do not wait until year end to determine if you have net earnings of $400 or more; do the calculations every quarter; 'cause you may be required to sent quarterly estimated payments to the IRS.

Source: http://www.irs.gov/

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