How long can you claim ten dependents with having any before you are penalized by the IRS?

Answer 1

If you mean how long can you claim them on the tax return (Form 1040) you file at the end of the year: You can do it until you get caught. Once you get caught, they will go back as far as they have records and charge you tax and penalties. There is no statute of limitations on tax fraud.

If you mean on the Form W-4 that you give to your employer: There is a misunderstanding here. You do not claim dependents on your W-4. You claim withholding allowances. Withholding allowances are not the same as dependents. Most people think they are and so they end up massively overpaying their taxes and then getting big refunds at the end of the year.

Most people, particularly if the job is their only real source of income, can claim far more withholding allowances than dependents and this is completely legitimate. Please use the following calculator from the IRS to get an estimate of how many withholding allowances you can claim:

http://www.irs.gov/individuals/article/0,,id=96196,00.html

Calculating the number of withholding allowances you can claim is not an exact science. You should aim to claim enough allowances so that you neither owe any money nor get any refund at the end of the year. You will not pay any underpayment penalty if you owe less than $1000 at the end of the year. The IRS will not bother you about the number of allowances you claim as long as your withholding turns out to be reasonably close to the amount of tax you owe. There can be a penalty (separate from the underpayment penalty) if you don't have a reasonable basis for the number of withholding allowances you chose. So use the calculator or fill out the worksheet that come with your W-4 to show how you arrived at the number.

Note: The IRS used to require employers to send in W-4 forms that showed more than 10 withholding allowances. They stopped doing this several years ago.