What happens by default in a blank married W4 form for tax withholding?

Thanks for explaining! So basically if we both submit blank MFJ W4s, we'd end up severely underwithheld because each employer would be calculating as if their job was the only household income? Would your recommendation be to follow the worksheet exactly, or is there a middle-ground approach that might work? $500 extra per check for me feels extreme, but I definitely don't want a huge tax bill next April.

Yes, that's exactly right. Each employer would calculate withholding as if their job was the only household income, which would put you in a lower tax bracket than your combined incomes actually place you in. I'd recommend following the worksheet fairly closely, though it doesn't have to be exact. The $500 might seem extreme, but consider your tax situation: when your $230K and her $85K combine, a significant portion gets pushed into higher tax brackets. One alternative approach is to use the IRS Tax Withholding Estimator online - it's more precise than the worksheet and might give you a more comfortable number. You could also start with a lower additional amount (maybe $350-400) and adjust mid-year after reviewing your withholding to ensure you're on track.

Does it handle state withholding too? I'm having this same issue with California state taxes where we're severely underwithheld since getting married, but the state forms are completely different from federal.

I'm skeptical about these online tools. How does it know what will happen with future income, especially for someone in sales where commission checks are irregular? Seems like it would just be making a best guess like the IRS calculator.

Yes, it handles state withholding too. I'm in Illinois and it calculated both federal and state withholding adjustments. It has specific support for California withholding which I know is particularly complex with their separate form system. For commission-based income, it actually has you upload several months of paystubs with your different commission amounts and creates a projection based on your actual earnings pattern. It's definitely more sophisticated than the simple IRS calculator. You can also manually adjust the projections if you know your commissions will be different in the coming year. Much more customizable than I expected.

Does that Claimyr thing actually work? The IRS phone system is the most broken thing I've ever experienced. Last year I called 14 times and never got through. How much does it cost?

I'm suspicious. How does a third-party service get you through to the IRS faster than calling directly? Sounds like they're just charging for something you can do yourself. The IRS is notoriously difficult to reach for everyone.

Yes, it absolutely works. The system basically monitors the IRS phone lines and calls you when it actually connects with a human agent. I went from spending 3+ hours on hold (only to get disconnected) to getting a callback when an agent was actually on the line. I don't want to discuss the exact cost here, but it was completely worth it considering I would have been underwithheld by thousands if I hadn't gotten the right guidance. The time savings alone was valuable - I estimate I would have spent 8+ hours trying to get through on my own based on previous experience. It's not some magic backdoor - they're using technology to handle the hold time for you. Think of it like paying someone to stand in line at the DMV for you. You still talk directly to the IRS agent yourself once connected.

That's interesting - I've seen that checkbox but wasn't sure exactly what it did. So it essentially reverts to withholding as if we were single filers? Would that be accurate if we both checked that box, or would it be too much withholding?

It doesn't revert completely to single withholding rates, but it's closer to that than the default married rate. If both of you check the box, you'd almost certainly be overwithheld based on your income levels. A better approach might be for just one of you to check the box (probably you since you're the higher earner) and then see how that looks after a couple of months. You can always adjust again. The problem with this method is it's not very precise - it's more of a blunt instrument compared to the extra withholding dollar amount approach, which can be fine-tuned. For your income levels, I'd estimate checking the box on both W4s would result in about $3,500-4,000 overwithheld for the year.

I tried that tool and it was ok but glitchy. It kept crashing when I entered my commission income because you have to break it down by pay period. Also doesn't handle things like RSUs or stock options well.

This is really helpful advice! I especially like the idea of scaling back the worksheet recommendation by 20-30% to start. The $500 extra per check did feel excessive, but $350-400 sounds much more manageable. One question - when you say having the lower earner add $50-75 per check, is that just for psychological balance or does it actually make a difference mathematically? I'm wondering if it matters which spouse's paycheck the extra withholding comes from, or if it all goes to the same place anyway. Also curious about your mid-year adjustment process - do you just look at your year-to-date withholding on your paystubs and compare it to what you think you'll owe, or is there a more systematic way to check if you're on track?

Great point about the psychological balance! Mathematically, it doesn't matter which spouse's paycheck the extra withholding comes from - it all goes to the same tax liability. But I found that splitting it helped us both feel like we were contributing to solving the problem rather than one person bearing the entire "penalty" of higher withholding. For mid-year adjustments, I use a simple spreadsheet approach: I take our year-to-date withholding from both paystubs, multiply our remaining paychecks by current withholding amounts, then estimate our total tax liability using the prior year as a baseline (adjusting for income changes). If the projected withholding is off by more than $1,000 in either direction, I adjust the W4s. The IRS also has a safe harbor rule - if you withhold at least 100% of last year's tax liability (110% if your prior year AGI was over $150k), you won't owe penalties even if you're underwithheld. So that's my backup target if the projections get too complicated with commission variations.

This is exactly the kind of professional insight I was hoping for! The 75% approach seems like a smart middle ground - starting with $375 extra for me and $75 for my fiancée feels much more reasonable than the full worksheet amount. I really appreciate the explanation about how each employer treats the income. It makes so much more sense now why the default withholding fails so badly with income disparities. The idea that each payroll system thinks it's dealing with our total household income explains why we'd be so underwithheld. One follow-up question: you mentioned getting within $1,000 of actual tax liability as the goal. Is that $1,000 in either direction, or specifically trying to avoid owing more than $1,000? I know there are penalty rules around underwithholding, so I'm wondering if it's safer to err on the side of slight overwithholding rather than risk owing a large amount. Also, when you say to recheck in June with actual married paystub data - are you referring to seeing how the withholding actually plays out in practice, or waiting until we're actually married and filing status changes take effect?

Great question about the $1,000 target! I meant $1,000 in either direction, but you're absolutely right to think about the penalty implications. The IRS safe harbor rules mean you won't face penalties if you either: (1) owe less than $1,000 at filing, or (2) withhold at least 100% of last year's tax (110% if your prior year AGI exceeded $150k). Given your income levels, you'll likely hit that 110% threshold, so I'd actually recommend erring slightly toward overwithholding rather than risk penalties. Better to get a refund than deal with estimated tax payment requirements. Regarding the June check - I meant after you're actually married and the new withholding has been in effect for a few months. You'll want to see how the adjusted withholding amounts are working in practice, especially with your commission variations. Sometimes the real-world numbers don't match the projections perfectly, particularly when one spouse has irregular income like yours. Plus, you'll have a better sense of your actual annual income by mid-year rather than just estimates.

Wow, $8,000 owed is exactly the kind of surprise I'm trying to avoid! Thank you for sharing your experience - it really drives home why I can't just assume the system will work itself out. The 70-80% approach you're suggesting seems to be a consistent theme in these responses, and it makes sense as a conservative starting point. I think I'll go with $375 extra for me and $75 for my fiancée as a starting point after we get married. One thing I'm curious about - you mentioned adjusting mid-year once you see how it's working out. How did you track whether you were on target? Did you just estimate your total tax liability and compare it to your year-to-date withholding, or did you use any specific tools or methods to stay on track? Also, after that first year surprise, how has your withholding strategy evolved? Do you still use the worksheet approach, or have you found other methods that work better for your situation?

After that expensive first-year lesson, I developed a pretty systematic approach to tracking our withholding throughout the year. I created a simple spreadsheet that I update quarterly with our year-to-date withholding from both paystubs, then project our total annual withholding based on remaining pay periods. I compare that to an estimated tax liability using the previous year's return as a baseline, adjusting for any major income changes. The key insight I learned is to use the IRS safe harbor rule as my floor - I make sure we're withholding at least 110% of the prior year's tax liability (since our AGI exceeds $150k) to avoid any penalties, even if my projections are off. As for strategy evolution, I actually moved away from the strict worksheet approach after year two. Now I use a "set it and forget it" method where I withhold about 25% of our gross income between both paychecks (factoring in pre-tax deductions). This tends to result in a small refund of $1,000-2,000, which I prefer over the stress of trying to get it perfect and risking another large tax bill. The peace of mind is worth the slight over-withholding to me. For someone just starting out like you, though, I'd definitely recommend the worksheet approach initially to understand how the numbers work, then you can adjust your strategy once you get comfortable with the system.