The more allowances you claim on line 5 of Form W-4, the less income tax will be withheld from your pay. In order to have the maximum amount of tax withheld, based on your filing status, you would enter “0” on line 5. This does not mean that you will not be claiming any exemptions on your annual tax return, or that you are waiving your right to claim exemptions. It is simply a way of having more tax withheld from your pay.
The number of allowances you can, or should claim, depends on several factors, including how many exemptions you expect you will be able to claim on your annual tax return; whether you have more than one job; what adjustments, deductions, and credits you expect to claim for the year; and whether you will file as head of household. And if you are married and your spouse works, you will need to decide on how many withholding allowances each of you will claim. This may depend on whether you plan to file jointly or separately, and if you file separately, who will claim exemptions for any qualifying dependents.