Reporting a zero cost basis is technically compliant since you're paying the maximum possible tax, but you're likely overpaying by a lot. For small amounts maybe it's worth the simplicity, but for OP's situation with $160k in sales, that would mean paying taxes on the full amount instead of just the gains.

This is really helpful advice! I'm new to crypto taxes and feeling overwhelmed. Your point about the IRS caring more about good faith effort than perfect precision is reassuring. I'm curious - when you say you used "conservative estimates" for the uncertain trades, do you mean you assumed higher purchase prices (better cost basis) or lower ones? And did you have to attach all that documentation to your return or just keep it for your records?

@Eva St. Cyr By "conservative estimates" I meant I assumed higher purchase prices when I was uncertain - basically giving myself a better cost basis rather than risking underreporting it. For example, if I remembered buying ETH sometime in a particular month but couldn't pinpoint the exact date, I'd use the highest price from that month rather than the average or lowest. You don't need to attach all the documentation to your return - just keep it organized in case of an audit. I created a master spreadsheet summarizing everything and kept all supporting documents (screenshots, emails, etc.) in a folder. The actual tax return just shows the summary numbers, but having that backup documentation ready gave me peace of mind. One thing I wish I'd known earlier - take screenshots of your current wallet addresses and transaction histories now while you still have access to them. Some platforms disappear or change their record-keeping, and blockchain explorers sometimes modify their interfaces.

Isn't there also the issue of state taxes? Some states don't recognize S corp elections or tax them differently. OP didn't mention their state residency situation but as an expat that might matter too.

This is exactly the kind of detailed breakdown I needed to see! Your point about the reasonable compensation requirement is crucial - I hadn't fully understood that only the salary portion would qualify for FEIE with S-Corp status. Given that my LLC income is typically around $85k annually and I qualify for the full FEIE, it sounds like staying as an LLC might actually be better for my situation. The SE tax savings from S-Corp election probably wouldn't offset losing FEIE benefits on the distribution portion. Do you remember roughly how long it took for the IRS to reject your electronically signed Form 2553? I'm hoping to get this resolved quickly so I can move forward with proper planning for 2024.

This is really helpful, especially the point about multiple jobs not "knowing" about each other! I'm dealing with this exact issue right now. My spouse and I both work part-time at different companies, and I think that's why our withholding has been so off. I tried filling out Step 2 on the W4 but got confused by all the calculations. Would it be simpler to just skip that section and add the extra flat amount like you suggested? Also, when you say $400-500 extra per month combined, would you recommend splitting that evenly between both their W4s or putting more on the higher earner's form? Thanks for breaking this down - it's exactly the kind of practical advice I was looking for!

You're absolutely right that the multiple jobs issue is tricky! For the W4 Step 2 - honestly, if it's confusing you, skip it and go with the flat extra amount approach. It's much simpler and will get you most of the way there. For splitting the $400-500 extra monthly withholding, either approach works fine. You could split it evenly ($200-250 each) or put more on the higher earner since they're likely in a higher tax bracket. The main thing is making sure the total adds up to what you need. One practical tip: start with a slightly higher amount (maybe $500-600 combined) for the first few months, then you can always dial it back if you're getting too big of a refund. It's better to overpay a bit and get money back than to still owe come tax time. You can always check your progress by looking at your paystubs to see how much total federal tax has been withheld year-to-date.

This breakdown is really helpful! The "catch-up" vs "ongoing" approach makes so much more sense than trying to figure out one big number. I like how you calculated the missing withholding amount and then spread it over the remaining months. Quick question though - when you say they should expect $10,000-13,000 in total federal taxes on $86k income, does that account for the standard deduction? I'm trying to make sure I'm not over-withholding for my aunt and uncle. They're married filing jointly with no other significant deductions beyond the standard amount. Also, keeping the paystubs to track progress is brilliant advice. I hadn't thought about monitoring it throughout the year rather than just hoping the math works out come tax time!

Yes, that $10,000-13,000 estimate does account for the standard deduction! For 2024, the standard deduction for married filing jointly is $29,200, so their taxable income would be around $56,800 ($86,000 - $29,200). At that level, they'd be mostly in the 12% tax bracket with some income potentially in the 22% bracket depending on their exact situation. The estimate also assumes they don't have significant other deductions or credits, so it should be pretty close for their situation. You're smart to double-check this - over-withholding isn't the end of the world since they'd get a refund, but under-withholding means another big tax bill. The paystub tracking really is a game-changer! I set up a simple spreadsheet to track total federal withholding year-to-date from each paystub, and it made it so much easier to see if we were on track or needed to adjust the extra withholding amount.

This is really helpful advice! I'm dealing with a Letter 12C right now and was freaking out about the deadline. It's reassuring to know that they'll still process late responses. Did you have to include any kind of explanation letter with your documents, or did you just send the forms they requested? Also, when you say "make copies of everything" - do you mean just for your own records, or do you send copies to the IRS and keep the originals?

Good questions! For the explanation letter, I just wrote a brief note saying "In response to Letter 12C dated [date], please find the requested documents attached." Nothing fancy - they mainly just want the forms they asked for. And yes, when I say make copies, I mean for your own records. Send copies to the IRS and keep the originals safe at home. Never send original documents to the IRS unless they specifically ask for them (which is rare). The copies are just as valid for their verification process. Also, if you're faxing, definitely keep that confirmation page! It's your proof that you submitted everything on time. I actually had to reference mine months later when there was a processing delay.

Thank you for sharing your experience! Your point about pandemic-related reporting changes is so important - I completely forgot that 2020 was such a messy year for tax documents. That actually makes me feel better about why they're asking for verification now, years later. Did you have any issues with unemployment compensation reporting? I received some unemployment in 2020 and I'm wondering if that might be part of why I got this letter. The letter mentions verifying income but doesn't specifically call out unemployment benefits. I still have all those 1099-G forms, so I could include them just in case. Also, 6 weeks for processing sounds reasonable. I was expecting it to take much longer based on all the horror stories I've heard about IRS delays!

This is exactly the kind of comprehensive analysis I was looking for! The NIIT calculation really changes the math - I hadn't fully considered that 27.8% effective rate on LLC income vs the 21% corporate rate. One question about the capital loss carryforward benefit you mentioned - if I'm doing mostly short-term trading, wouldn't most of my losses be ordinary losses rather than capital losses? Or does the C Corp structure somehow convert trading losses to capital losses that can be carried forward more favorably? Also, regarding documenting business purpose for retained earnings - what kind of documentation would satisfy the IRS? Is it enough to have a written investment policy stating the corporation's growth strategy, or do they expect more detailed justification for each year's retained profits? The indefinite capital loss carryforward could be huge if I have a bad trading year early on. That alone might justify the C Corp structure even with the double taxation risk down the road.

Great questions! Regarding loss treatment - you're right to think about this carefully. For C Corps engaged in trading, the losses would generally still be ordinary business losses, not capital losses. The key advantage isn't about converting the character of losses, but rather that C Corps can carry forward ordinary business losses indefinitely (subject to certain limitations), while individual traders face the $3,000 annual limit on capital loss deductions against other income. However, if your C Corp is classified as an "investment company" rather than actively trading, then the losses would be capital losses with the indefinite carryforward benefit I mentioned. The distinction between trader vs investment company for C Corps follows similar but not identical rules to the individual trader vs investor determination. For documenting retained earnings business purpose, you'll want more than just a general investment policy. The IRS expects specific, reasonable business needs for the retained funds. Examples include: documented plans for expanding trading capital to take advantage of larger opportunities, maintaining cash reserves for margin requirements, funding technology upgrades or research tools, or accumulating funds for specific investment strategies that require substantial capital. Annual board resolutions explaining the business reasons for retention, along with supporting financial projections, are typically recommended. The key is showing the retention serves the business rather than just avoiding personal taxes.

That's a really practical perspective on the compliance costs and complexity. I've been so focused on the tax rate differences that I hadn't properly factored in the ongoing operational expenses. $2,000-5,000 annually in professional fees could easily wipe out tax savings in the early years when profits might be modest. The hybrid approach you mentioned is intriguing - starting with LLC simplicity and converting later. Do you happen to know what the typical threshold is where people make that conversion? Is it based on annual profits, total assets under management, or some other metric? Also, regarding the tax rate volatility risk you mentioned - that's something I hadn't considered but it's a valid concern. Given the current political climate, locking into a C Corp structure based on today's 21% rate could backfire if corporate rates increase significantly in the coming years. At least with pass-through taxation, any rate changes would affect me the same whether I'm operating through an entity or individually. This conversation has really helped me realize that maybe I should start simple with an LLC (without S-Corp election initially) and focus on building consistent profits before getting too fancy with the structure. The conversion option gives me a safety valve if the numbers eventually justify the additional complexity.