There's no federal process for "registering" a foreign marriage in the US. Some states allow you to record a foreign marriage certificate with the county clerk's office, but it's not required and doesn't change the validity of your marriage for federal purposes. The most important thing is having your original marriage certificate (and possibly a certified translation) available if you ever need to prove your marriage for any legal purpose. But for tax purposes, you're already doing the right thing by filing as married.

This is exactly the kind of professional reassurance I needed to hear! As someone new to dealing with international marriage tax issues, it's so helpful to get confirmation from an experienced tax preparer. I was getting really anxious about potentially making the wrong choice, but hearing that this is a common situation you've handled many times makes me feel much more confident. Thank you for taking the time to explain this clearly!

That's a good point! I'll have him check with HR to see exactly what he put on his W-4. He said they just handed him a bunch of forms to fill out on his first day and he wasn't really sure what some of them meant. Better to catch any mistakes now rather than at tax time!

This is such helpful advice about tracking earnings! I never thought about having my son keep a running total. The spreadsheet idea is perfect - I'm definitely going to help him set that up this weekend. One question though - you mentioned he might be owed a refund on Social Security/Medicare taxes if his earnings are very low. I thought those were always required regardless of income level? When would someone get those back?

Is there any calculator that works for international situations? The IRS withholding calculator seems to break when I try to enter foreign income.

Unfortunately the standard IRS calculator isn't designed for international situations. Your best bet is to use a tax professional who specializes in expat taxes or international situations. Alternatively, you can estimate your total tax liability using last year's tax brackets, then divide by your pay periods and add extra withholding accordingly. I usually recommend withholding a bit extra if you're uncertain. You can always adjust your W4 later in the year if you realize you're withholding too much.

Where do you even find these tax treaties? Is there a database somewhere?

Great questions! For the tax forms, mileage reimbursements at the IRS standard rate don't need to be reported on any tax forms as long as they're properly documented and don't exceed the standard rate. They don't go on the W-2 and you don't issue a separate 1099 for them. As for tracking, a simple written log is generally sufficient for IRS purposes. The key elements are date, business purpose, starting location, ending location, and total miles. Photos of the odometer aren't required, though some families prefer them for extra documentation. The IRS mainly wants to see that you have a contemporaneous record (meaning it's recorded at or near the time of the trip, not reconstructed later). Just make sure to keep these mileage logs separate from other employment records - it helps show they're legitimate business expense reimbursements rather than additional compensation.

1 That's a great point about the 60-day window! I'm definitely past that now since this all started in February. Would this affect how I need to handle the taxes differently? And have you ever successfully gotten a company to issue a corrected 1099-R? Vanguard has been so unhelpful so far that I'm not optimistic.

21 Since you're past the 60-day window, your approach of doing the Roth conversion was exactly right - it's essentially a "fix" that works within the current tax rules. The 60-day rule would have applied if you were trying to get the money physically returned and then redeposited correctly. I have successfully received a corrected 1099-R, but it took persistence. The key is to talk specifically to their tax reporting department (not general customer service) and clearly explain that the current coding is factually incorrect. Reference specific IRS publications like Publication 590-A regarding rollovers with after-tax contributions. It's definitely worth trying, but prepare your Form 8606 correctly regardless of whether they fix their 1099-R.

8 The pro-rata rule only applies when you have a mix of pre-tax and after-tax money in IRAs. The basic calculation is: (after-tax amounts ÷ total IRA balance) × conversion amount = non-taxable portion. Generally, if you're in a lower tax bracket now than you expect to be later, converting more at once makes sense. If you expect to be in a lower bracket in future years, spreading conversions out could save on taxes. For after-tax 401k earnings specifically, you'll pay taxes now if you convert them to Roth, or later if you keep them traditional. The main advantage of converting is that all future growth becomes tax-free, not just the original earnings.

15 The timing decision really depends on your current vs expected future tax brackets. One strategy I've seen work well is to convert just enough each year to "fill up" your current tax bracket without pushing you into the next one. For your specific situation with after-tax 401k earnings, you might want to run the numbers both ways. Calculate what you'd pay in taxes now on those earnings versus what you might pay in retirement (considering that traditional IRA withdrawals are taxed as ordinary income, not capital gains). Also keep in mind that Roth conversions can affect other tax situations - like IRMAA surcharges for Medicare if you're near retirement age, or impact on financial aid if you have kids in college. The "all at once vs. spread out" decision isn't just about tax rates.