Estimated Taxes — What They Are Why They Matter and How to Handle Them

In this episode of ThimbleberryU, we dive into a topic that often catches even financially savvy people off guard—estimated taxes. Many assume taxes are fully handled through paycheck withholdings, but we unpack why that assumption can lead to nasty surprises, especially for professionals in tech and healthcare.

We start by defining what estimated taxes are: quarterly payments made directly to the IRS when withholding isn’t enough to cover total tax liability. This often applies to small business owners, but also to high-income W-2 employees who receive RSUs, ESPP income, large bonuses, or mid-year raises. Amy shares real-life examples of clients whose withholding fell short, either because RSUs were taxed at a flat 22% while their actual bracket was higher, or because payroll systems didn’t account for mid-year raises, leading to unexpected tax bills and underpayment penalties.

We then explore the IRS’s pay-as-you-go approach. If you've underpaid during the year—even if you pay in full by April—you could still face penalties. Jag and Amy emphasize how the system annualizes income, so a raise in July can retroactively affect your tax liability starting in January. This is where estimated taxes kick in, sometimes unexpectedly after filing the previous year’s return.

To determine whether you're subject to these payments, we explain the IRS safe harbor rule: if you pay 90% of your current year’s liability or 110% of the prior year’s, you generally avoid penalties. We walk through the process of calculating your total tax liability, subtracting what’s already been withheld, and deciding how to handle any shortfall—either through increased paycheck withholding or quarterly payments to the IRS and state.

Amy reminds us that overpaying gives the IRS an interest-free loan, so it's often best to aim for accuracy. Tools like financial planning software and coordination with a CPA can make this process manageable. The key is to review and adjust quarterly so you’re not blindsided come tax time.

We close with key takeaways: estimated taxes aren’t just for freelancers, income changes—whether yours or a spouse’s—can affect your liability, and proactive planning with a financial advisor and CPA helps avoid surprises. Most importantly, working with both professionals ensures smoother execution and better results.

To get in touch with Amy and her team at Thimbleberry Financial, call 503-610-6510 or visit thimbleberryfinancial.com.