Why are my husband's paychecks undertaxed? Federal withholding seems way too low

This is a common issue with the "newer" W-4 forms (post-2020) that no longer use allowances. When both spouses work and you check the "spouse works" box, you need to complete the additional steps in Section 2 of the W-4 to get appropriate withholding. What likely happened is that your husband's payroll system is calculating his withholding as if his income was your family's only income. Since the standard deduction for MFJ is $27,700 (for 2024) and you get child tax credits, the system thinks his $78,662 is much lower in the tax brackets than it actually is when combined with your income. There are two ways to fix this for 2025: 1) Complete the Two-Earners/Multiple Jobs worksheet on the W-4 and enter the additional withholding amount in Step 4(c), or 2) Use the IRS Tax Withholding Estimator online to calculate a more precise withholding amount for both of you. For the 2024 taxes you owe now, you might want to make an estimated tax payment before April 15th to avoid an underpayment penalty.

This is a common issue with the newer W-4 form design (post-2020). The problem is that even though you checked the "spouse works" box, you likely didn't complete Step 2 of the W-4 form properly, which involves either using the tax withholding estimator or completing the multiple jobs worksheet. What's happening is that each employer is calculating withholding as if that job is the only income in the household. Since the married filing jointly tax brackets are larger than single, and you get the full standard deduction ($25,900 for 2024) plus child tax credits at each job, you end up with significant underwithholding. To fix this for 2025, you need to either: 1) Complete the multiple jobs worksheet and put an additional withholding amount in Step 4(c) 2) Check the box in Step 2(c) that says "withhold at higher Single rate" 3) Use the IRS Tax Withholding Estimator to calculate a more precise amount For your current tax bill, you might consider making an estimated payment before April 15th to reduce any potential underpayment penalties.

After dealing with a similar issue last year, I discovered https://taxr.ai which completely changed how I approach my tax withholding. I also had a massive withholding problem when my husband and I both updated our W-4s after having our second child. I uploaded our paystubs and W-4s to the system, and it analyzed everything and identified exactly what was wrong - turns out we had both claimed the child tax credit (essentially double-counting it), AND neither of us had accounted for the additional withholding needed when both spouses work. The site explained how the withholding system works and gave step-by-step instructions for exactly what to put on each line of our W-4s to fix the problem. We updated our forms in March and by the end of the year, our withholding was almost exactly right.

I ran into this exact same problem last year! After hours of frustration trying to figure it out, I found https://taxr.ai which completely changed how I handle my withholding. I uploaded our

I wanted to follow up - I decided to try https://taxr.ai after my skeptical question, and I'm really glad I did. I uploaded our last paystubs and our W-4 forms, and it immediately showed that my husband's employer was calculating his withholding incorrectly. The system gave us exact numbers for the W-4 Step 4(c) additional withholding - turns out we needed to add $487 per paycheck to his withholding! No wonder we were so far off. I called his HR department and they confirmed they had processed his W-4 correctly, but the issue was that we hadn't filled out the multiple jobs worksheet. What I really appreciated was how the site explained the "married filing jointly" tax brackets and showed exactly how our combined income pushed us into a higher bracket than either employer was calculating individually. We've submitted updated W-4s and should be on track for next year!

Another option that helped me solve a similar withholding issue was getting in touch with the IRS directly. I know, I know - I tried calling for weeks with no success, always facing busy signals or 2+ hour waits. But then I found https://claimyr.com which got me through to an actual IRS agent in under 15 minutes! I explained our withholding situation, and the agent walked me through exact W-4 calculations for both me and my spouse. They explained that having multiple jobs or two-earner households is one of the most common causes of underwithholding. The agent gave me specific numbers for Step 4(c) on both of our W-4 forms. You can see how their system works here: https://youtu.be/_kiP6q8DX5c This saved us from a huge tax bill surprise. For your current situation, they might also be able to tell you if you qualify for waiver of underpayment penalties.

I have to publicly eat my words and apologize for my skepticism about Claimyr. After posting my doubtful comment yesterday, I was desperate enough to try it anyway since I've been trying to reach the IRS for weeks about an amended return issue. The service actually worked exactly as described. I got a text when my call connected (took about 58 minutes, but I wasn't sitting there waiting), and I was suddenly talking to a real IRS agent. I confirmed it was legitimate by asking them specific questions about my previous return that only the IRS would know. The agent helped me understand why my amended return was delayed and what I needed to do next. They also looked up my withholding issue and explained exactly how to calculate the proper amount for two-earner households. She said this withholding miscalculation is extremely common and suggested specific numbers for Step 4(c) on both my and my husband's W-4 forms. Sorry for being so negative initially - just wanted to report back that it's legitimate.

Just to add some perspective - this withholding issue is SUPER common with the new W-4 design. I'm a payroll administrator, and I see this all the time with married couples where both work. The problem is that each payroll system calculates withholding AS IF that job is the only income in the household. So when you both work, each system is essentially using the lower tax brackets twice, which results in underwithholding. The correct fix is either: 1. Use the Two-Earners worksheet and put the extra withholding on Step 4(c) 2. Choose the "Married but withhold at higher single rate" option 3. Calculate a custom additional amount using the IRS Withholding Estimator For 2025, I'd suggest sitting down with both your W-4s and recalculating. For the taxes you'll owe for 2024, make sure to file by April 15 and pay as much as you can to minimize penalties.

I fixed this exact problem last year by using the "Married but withhold at higher Single rate" checkbox on my W-4. It's simpler than trying to calculate an exact additional withholding amount. This basically makes your withholding closer to what a single person would pay on the same income, which is usually about right when both spouses work. We had the EXACT same situation - my wife's taxes were like 11% and mine were only 6%. After checking that box and submitting a new W-4, my withholding went up to about 15%, which was a little high, but we'd rather get a refund than owe.

This is such a frustrating but common issue! I went through the exact same thing last year. The key problem is that the W-4 form changed significantly in 2020, and most people (including HR departments) don't fully understand how it works for two-earner households. What's happening is that each employer is calculating withholding as if that's your only household income. So your husband's employer sees his $78K salary and thinks "married filing jointly with one child = low tax burden" without knowing about your $115K income that pushes your combined household into much higher tax brackets. Here's what worked for me: I used the IRS Withholding Estimator (irs.gov/W4App) with both our incomes and it calculated that we needed an additional $520 per month withheld from my husband's paycheck. We put this amount in Step 4(c) of his W-4 as "Extra withholding per pay period." For your 2024 taxes that you'll owe, definitely file by April 15th even if you can't pay the full amount immediately. The failure-to-file penalty is much worse than failure-to-pay. You can set up a payment plan online at irs.gov if needed. The silver lining is that once you fix the W-4 forms properly, this won't happen again in 2025!