Why do I owe so much to federal taxes?

[KristinS1]

Both my husband and I claim "0" on our W4s. My husband did get a new job in February of this tax filing season but nothing else has changed. Yet I owe almost $900 to federal.

[Mike9241]

since we don't know your income it's hard to say wether owing $900 is a lot

this is what the w-4 says for step 2

(b) Use the Multiple Jobs Worksheet on page 3 and enter the result in Step 4(c) below; or
(c) If there are only two jobs total, you may check this box. Do the same on Form W-4 for the other job. This
option is generally more accurate than (b) if pay at the lower paying job is more than half of the pay at the
higher paying job. Otherwise, (b) is more accurate .

none of these methods are truly accurate especially if pay varies from pay period to pay period or you get bonuses or other forms of additional compensation.  also if you have non-wage income that can result in you owing.

[Vanessa A]

The most likely reason is that each employer withheld your taxes at the rate you would be liable for if you only had one income for the house.

Example.  You are married and earn $45,000 at of your job with a tax bracket of 12%  ($4,989) and he earns $45,000 at his job where his employer withheld $4,989 as well.  So each employer withheld the correct amount based on what you earned with them. In total they withheld $9,978 .  

However, when you combine your wages from all 4 jobs, your income is $90,000.  This puts you in the 22% bracket for part of your income.  So, your total tax liability would be $11,397  This would mean you had $1,419 too little withheld and would owe it when you filed your taxes. 

You may want to complete a new W4 form for the one you make the most for or even for 2 of them.  You will want to  complete section 2 and probably section four to have an additional amount withheld every pay period.

You can calculate the amount extra to be withheld, if your job situation is not expected to change, by dividing your $900 (or more if you would prefer to have a refund and not risk owing again) due by the number of pay periods you have in a year (usually 26 or 52) and entering that on line 4c.

Depending on the state you live in and if they have a flat rate or a graduated rate like the federal government does, you may or may not need to make changes.

In the meantime, if you are unable to pay your taxes in full, you should still file by April 18th, but you can apply for a payment plan from the IRS.  When you get to the end of TurboTax, prior to hitting file, it will give you the option to apply.