"My husband is the only earning member & he supports all our expenses. For the tax year 2009 can my husband claim me & my children as dependants?"Spouses are not dependents of each other. Instead, husbands and wives can choose either to file a joint tax return or to file two separate returns. Filing jointly provides you with two personal exemptions for the husband and wife, plus one personal exemption for each dependent. Filing jointly also provides a standard deduction of $11,400 for 2009. You can also itemize, if that figure will be higher than your standard deduction.
How do all these numbers work together? These standardized about are tax deductions you can take, which reduce your income before any tax is calculated. Or to phrase it another way, these deductions create a zero-percent tax bracket for you. For a married couple with no dependents, their first $18,700 of income is tax free. After that, their income would start being taxed using various tax rates.
Generally, taxes are lower when filing jointly, as the tax brackets are much wider (thereby allowing more income to be taxed at lower rates) and joint filers are eligible for a wider range of tax deductions and credits.