If you earn zero income this year, you don't have to file a tax return. Even if you have some money coming in, the IRS has a minimum income level for submitting your 1040; below the cutoff point, you don't have to file. The cutoff varies with your age and your filing status.
Like most figures in the tax code, the cutoff point rises over time to allow for inflation. If you're a single filer under 65 in 2012, for example, you start paying taxes when your taxable income reaches $9,500. If you're a married couple filing jointly and both over 65, you need a combined income of $21,300. When you're a single dependent under 65, you pay if you earn $5,800 or receive $950 in unearned income such as dividends.
Social Security Benefits
The rules change if you receive Social Security retirement, survivor or disability benefits. When Social Security is your entire income, you usually pay nothing. If you have other taxable income, add it to half your Social Security benefits. Then add any tax-exempt interest you received this year. If the total is $25,000 or more — $32,000 for joint returns — some of your benefits are taxable. For married couples filing separately, getting any taxable income makes benefits taxable.
Social Security Taxes
Even if you don't earn enough to pay income tax, your employer has to take withholding out for Social Security and Medicare. If you earn tip income you don't report to your employer, you have to report it yourself at the end of the year and pay the taxes, even if you pay no income tax. When you work as an independent contractor, you pay self-employment tax — the equivalent of Social Security and Medicare — any time your net income is over $400.
Your employer may have taken out income tax withholding from your paycheck, thinking your annual income would be higher. Even if your income fell below the cutoff, you need to file if you want the IRS to cut you a refund check. You also need to file to qualify for any of the tax credits that pay you back more than you paid in. The Earned Income Tax Credit and the Additional Child Tax Credit fall into this category.