W4 Withholding 2025 MFJ

[ZAG1265]

Just got married, filling our W4 as MFJ, no dependents.

I used the IRS Tax Estimator, and it has me putting $1500 in deductions (4b) and $350 each pay period under additional withholdings (4c).

Two questions:

1. Why do we have to withhold additional income for each pay period?

2. The IRS has me putting $350 of extra withholding under my W4 and has my spouse putting $0 under extra withholding (4c). Are we allowed to split the additional withholding in half for each W4 ($175 for each of our W4s)?

[SharonD007]

Based on the information that you entered in the IRS Tax Estimator, it appears that you and your spouse don't have enough withholding, so the estimator is calculating that you pay the additional amount.  

Yes, you can split the extra withholding in any way that you like.

You can also try the  TurboTax W-4 Calculator 2024.

[ZAG1265]

Is there a reason it says we’re not withholding enough? I provided the exact numbers from our paystubs, so shouldn’t the government already be withholding the correct amount of taxes? 

[NicolleR1]

There are multiple reasons that could lead to not having "enough withholding" such as having multiple jobs, or having different source of income, such as self employment income or investment income. Another factor could be that both income combined put you in a higher tax bracket. 

It might also be an issue within the company you work for. You can check with your company's Payroll or HR department to see why are they not withholding enough.

[ZAG1265]

We did just get married, so I wonder if it’s because I’m changing from filing single to filing married joint. But I thought filing married joint would usually reduce our tax burden.

[LeticiaF1]

Yes, filing married filing joint is usually more advantageous because it gives you more deductions and credits and usually has a lower tax rate.  However, if you both had income and are now combining them probably put you in a higher tax bracket, as NicolleR1 mentioned.  

@ZAG1265