Hello, I bought a house this year and just got married. My husband has an ITIN number and no social security number. We both work. We have no children. Our total income is about $90,000/yr. We will be filing our taxes as married/jointly. I need to change my w4 for work. I am confused if I should have "1" or "2" for total allowances claiming. It is also difficult for me to determine deductions as I don't know my home mortgage interest as this will be my first year owning a home. Basically I just don't want to end up paying a lot when we file our taxes! Please help.

#1:I assume that you are a US resident(a G/C holder) or a citizen, then as yur spouse also has income in US, you can file your return as MFJ;as you are married and one spouse , you, is a U.S. citizen or a resident alien and the other spouse is a nonresident alien, you can choose to treat the nonresident spouse as a U.S. resident. This includes situations in which one spouse is a nonresident alien at the beginning of the tax year, but a resident alien at the end of the year, and the other spouse is a nonresident alien at the end of the year. You need to calculate the total number of exemptions. Generally you can claim yourself, your spouse. The second page of the W-4 form contains a worksheet to help determine the number of allowable exemptions. However, if you are still unsure as to how many exemptions to claim, you need to visit the IRS website and access the IRS Withholding Calculator; please IRS website here and follow the instructions ; 2013 Withholding Calculator

Then, you need to submit the completed form to your employer. Be sure to keep a copy of your completed and signed W-4 for your files
NOTE: the more allowances that you claim on your W-4 form, the less money will be withheld from your paycheck for federal income taxes. Examples of when you may be entitled to claim more allowances include getting married. Each allowance you claim reduces the amount of income subject to federal income tax withholding. For 2013, each allowance claimed reduces your annual income subject to withholding by $3,900.SO, Do not claim more allowances than you are entitled to claim. Improperly claiming allowances on your W-4 form can lead to both civil and criminal penalties. Contact your HR dept for more info . Legally you can declare 9 exemptions on your w4 without submitting a reason, but be careful doing this, you don't want next April to come around and discover you owe a whole bunch of taxes because you didn't have enough taken out.
In general, the more allowance you claim, the less tax money is withheld from your paycheck and vice versa.


#2:OK to deduct your home related expenexess,i.e., mortgage interest exp/ pty tax, or etc, you need to itemize your deductions on Sch A of 1040, so UNLESS you itemize your deductions on yur return, you can’t deduct your mortgage interest exp.