The Additional Medicare Tax at $200k is definitely a curveball that catches a lot of people off guard. I went through this exact situation two years ago when my income jumped from $185k to $230k due to a promotion and larger bonus structure. Here's what I learned the hard way: the key is to treat your base salary and bonus as separate withholding calculations. For your regular paychecks, you can use the IRS withholding calculator to determine the right additional amount for line 4(c) of your W-4. I ended up adding $312 per biweekly paycheck to cover the additional tax burden. For the bonus component, since it's taxed as supplemental income at the flat 22% rate (plus the 0.9% Additional Medicare Tax on amounts over $200k), you need to calculate if that withholding will be sufficient. In most cases with a 25% bonus component, you'll need additional withholding from your regular paychecks to cover the shortfall. One strategy that worked well for me was to calculate my total expected tax liability in January, subtract all expected withholding (including the flat rates on bonuses), then divide the difference by my remaining pay periods. This gave me a specific dollar amount to add to each regular paycheck. Also consider maxing out your 401(k) early in the year if possible - this reduces your taxable income during regular pay periods and gives you more take-home pay when you need it most, before the bonus hits.

I'm dealing with a very similar situation and wanted to share what's been working for me so far. I crossed $200k for the first time this year (base salary $165k plus quarterly bonuses that will likely total around $50k). What I found helpful was using the IRS withholding estimator quarterly rather than just once at the beginning of the year. Since your bonus amount can vary, I recalculate my withholding needs after each quarter based on actual YTD income and update my W-4 accordingly. For the Additional Medicare Tax specifically, I learned that your employer will automatically start withholding the extra 0.9% once your YTD wages exceed $200k, but they don't look at your projected annual income. So if you get a large bonus early in the year that pushes you over $200k, you might have too much Additional Medicare Tax withheld if your total annual income ends up being closer to the threshold. I've been setting aside 30% of each bonus payment in a separate account, then making estimated tax payments quarterly based on where my projections stand. This gives me more control than trying to perfectly calibrate payroll withholding, especially with the variable bonus component. One thing I wish someone had told me earlier: the $200k threshold is per person, not household. So if you're married filing jointly, each spouse gets their own $200k threshold for the Additional Medicare Tax (though it's $250k combined for other purposes).

Has anyone actually had the IRS come after them for this specific issue? I've been using W8BEN for my Singapore company for 3 years now and just learned from this thread I should be using W8BEN-E! Need to know how urgent this is to fix...

I went through almost the exact same situation with my German GmbH! Used W8BEN for nearly 3 years after incorporating before realizing my mistake. What really helped me was documenting everything - when I discovered the error, when I submitted corrected forms, and keeping records of all payments received during that period. From my research and speaking with a cross-border tax specialist, the key factors that work in your favor are: 1) You were still properly certifying your non-US status (just on wrong form), 2) You corrected it as soon as you realized, and 3) The US platforms likely applied correct withholding rates anyway since UK individuals and UK corporations often get similar treaty treatment. The IRS tends to focus on cases where taxes were actually avoided or where there's clear intent to deceive. Your situation sounds like a genuine administrative oversight that you've now corrected. I'd recommend keeping good documentation but not proactively contacting the IRS unless you discover actual withholding discrepancies in your payment history.

I'm in almost the exact same situation! Filed my joint return last week and used my individual Chime account. Now I'm seeing all these mixed experiences and getting nervous. For what it's worth, I called Chime customer service yesterday and they said they "generally accept tax refunds regardless of the filing status" but couldn't guarantee anything. The rep mentioned they evaluate each deposit individually. I'm keeping my fingers crossed, but if I had seen this thread earlier I probably would have gone with the paper check option. Will update if/when my refund comes through to add another data point for future filers!

Based on all these mixed experiences, it seems like Chime's acceptance really varies case by case. I've been using Chime for my individual returns for the past two years without issues, but this is my first year filing jointly with my spouse. Reading through everyone's experiences, I'm leaning toward just requesting a paper check to be safe. The potential 6-8 week delay if it gets rejected isn't worth the risk, especially since you mentioned needing the money for quarterly estimates. Better to wait a few extra days for a guaranteed paper check than potentially wait months for a reissued one after rejection. Thanks everyone for sharing your real experiences - this is exactly the kind of info you can't find in official FAQs!

One thing to remember is that if your non-refundable credits exceed your tax payable, you don't get to carry forward the unused portion (with a few exceptions like tuition credits). This is different from refundable credits like GST/HST credits that can actually generate a refund regardless of your tax owing. For example, if your tax owing is $5,800 but you have $7,000 in non-refundable credits, your tax is reduced to $0, but you "lose" the extra $1,200 in credits. This is why they're called "non-refundable" - they can't generate a refund by themselves.

Jst wanted to add that one of the most commonly overlooked things is that u should maximize ur RRSP contributions if u have room. This will lower ur net income which reduces the taxes owing BEFORE the non-refundable credits are applied! Double win!

Don't forget to check your state tax records too! This happened to me and the scammer filed fraudulent returns at both federal AND state levels. Each state has their own process for handling tax identity theft. Contact your state tax agency immediately. Also check if your health insurance information was compromised, since they might have used your identity for medical benefits too.

I'm so sorry this happened to you! Tax identity theft is unfortunately becoming more common, but you're handling it well by taking action quickly. In addition to all the excellent advice already shared, I'd recommend keeping detailed records of every phone call, form submission, and piece of correspondence related to this case. Create a dedicated folder (physical or digital) with dates, reference numbers, and notes from each interaction. Also, consider requesting your IRS transcripts online through the IRS website - this will show you exactly what returns were filed under your SSN and when. It can help you build a timeline of the fraud and provide concrete evidence when speaking with IRS agents. One thing that helped me when I dealt with a similar situation was setting up an IRS online account if you haven't already. This gives you direct access to your tax records and can alert you more quickly if suspicious activity happens in the future. The IP PIN you mentioned is definitely crucial - make sure to request it as soon as your case is resolved. Stay persistent but patient. The process is frustrating, but the IRS does eventually resolve these cases. Document everything and don't hesitate to escalate to the Taxpayer Advocate Service if you hit roadblocks.