Has anyone considered that the interest rates might change? The IRS adjusts these quarterly. If the Federal short-term rate drops, so will the overpayment interest rate. So even if this crazy scheme worked (which others have pointed out it doesn't), you'd have no guarantee of keeping that 7% rate for long.

As someone who works in financial compliance, I wanted to add that the IRS also has sophisticated data analytics that can easily identify patterns inconsistent with normal taxpayer behavior. They cross-reference your payment patterns with income reported on W-2s, 1099s, and previous returns. If you suddenly start making massive estimated payments that don't align with your reported income or business activity, it will trigger automated flags in their system. They can then demand documentation justifying these payments, and if you can't provide legitimate business or income reasons, they'll process an immediate refund - often within days rather than the normal processing time. The system is specifically designed to prevent exactly what you're thinking of doing. Your best bet for earning decent returns is still traditional investment vehicles like I-Bonds, CDs, or high-yield savings accounts that are actually meant for storing money.

Has anyone used the IRS Direct Pay system for their quarterly payments? I've heard horror stories about payments not being properly credited to accounts or applied to the wrong tax year. Trying to decide between that and EFTPS.

Great question! I went through this exact transition two years ago and the safe harbor rule was a lifesaver during that first year of uncertainty. One thing I'd add to the excellent advice already given - don't forget to consider your state estimated tax requirements too if you're in a state with income tax. Some states have their own safe harbor rules that might be different from federal, and you'll want to make sure you're covered on both fronts. Also, since you mentioned your income is likely to increase but uncertain, you might want to reassess after your second quarter payment. If your income ends up being significantly higher than expected, you can always increase your remaining quarterly payments to avoid a large balance due at filing time, even though the safe harbor protects you from penalties. The 110% safe harbor rule is definitely the way to go for your first year of self-employment - it takes so much stress out of the guessing game while you figure out your new income patterns. Once you have a full year of self-employment income under your belt, you'll have a much better sense of what to expect for the following year.

8 Microsoft has a free online version of Office (Word, Excel, PowerPoint) that you can use through a web browser at office.com. It's not as full-featured as the desktop version but might be enough for basic work tasks without having to pay for a subscription.

Another alternative worth considering is LibreOffice, which is completely free and open-source. It's compatible with Microsoft Office file formats and includes Writer (Word equivalent), Calc (Excel equivalent), and Impress (PowerPoint equivalent). While it may have a slightly different interface, it handles most business tasks well and could be a good temporary solution while you work on getting your employer to provide or reimburse the Microsoft Office subscription. I've used it for basic document editing and spreadsheet work and found it quite capable for most standard office tasks.

Has anyone actually withdrawn their excess HSA contribution? I called my HSA provider (HealthEquity) about this and they made it sound super complicated. They said I needed to request a "distribution of excess contributions" and that I'd get a special tax form for it. But then I'd need to sort out how much earnings those excess contributions had made?? How do you even calculate that? The whole thing sounds like a headache.

I went through this exact situation two years ago and wanted to share what I learned. First, definitely get that $125 distribution error fixed on your amendment - the IRS can be picky about HSA reporting accuracy. For the $550 excess, I'd strongly recommend calling your HSA provider ASAP to request a return of excess contributions rather than carrying it forward. Even though you've already filed, you likely still have time if you're within the extended deadline (October 15th). Here's why this approach is better: when you carry forward an excess contribution, you'll pay the 6% excise tax ($33) this year, and if you mess up the math on reducing next year's contributions (which is easy to do), you could end up paying the penalty multiple years. I made that mistake and ended up owing penalties for three years before I figured out how to properly "use up" the excess. The return of excess contributions route means you pay tax on any earnings, file one amendment to fix everything, and you're done. Much cleaner. Your HSA provider should be able to calculate the earnings portion automatically - you don't have to figure that out yourself.

Don't forget about potential foreign exchange implications! If you're sending USD to a foreign sub that operates in another currency, you'll need to account for forex gains/losses on those intercompany loans. This can get messy depending on the functional currency of each entity and how often exchange rates fluctuate.

One thing I haven't seen mentioned yet is the importance of considering your state tax implications as well. Many states have their own rules around intercompany transactions and transfer pricing that don't always align with federal treatment. For example, some states require separate accounting for intercompany interest income/expense, and others have specific addback requirements that could affect your state tax liability. California and New York are particularly aggressive in this area. Also, since you mentioned this is your first time dealing with international tax at scale, I'd strongly recommend getting a transfer pricing study done by a qualified professional if your transaction volumes are significant. The IRS has been increasingly focused on intercompany pricing audits, especially for tech companies with IP development across multiple jurisdictions. Having proper documentation upfront is much cheaper than trying to reconstruct it during an audit.