You Made More Money This Year. Here’s the Tax Move You Probably Missed

“I made a lot more money this year than last year. Am I about to owe the IRS a huge bill?” If that’s the question you typed into a search bar at 11 p.m., the honest answer is: probably yes, and probably more than you think.

A raise. A bonus. Some 1099 income on the side, maybe a partner moving in with their own paycheck. All good news, and all capable of pushing you into a place your withholding was never set up to handle.

The rest of this piece follows one imaginary but very ordinary reader. Call them someone in their late 20s who had a comfortable W-2 salary last year and will land at a meaningfully higher total this year, thanks to a promotion and a freelance gig on the side.

Their W-4 hasn’t been touched in years. Everything that goes wrong for them goes wrong for a lot of people in their 20s and 30s. Let’s walk through it.

The Raise Isn’t the Problem. The Untouched W-4 Is

Our newly higher earner assumes their employer handles taxes correctly. Payroll takes something out every check. It shows up on the pay stub. Case closed, right?

Not quite. A W-4 tells your employer how to withhold based on the picture you gave them the day you filled it out. If that day was a few years ago, when you were making noticeably less, the form is still assuming a version of your life that no longer exists. Payroll systems don’t magically know you got promoted, picked up a second job, or started a Shopify store on weekends.

The move nobody talks about is boring and free: pull up your most recent pay stub, plug the numbers into the IRS Tax Withholding Estimator, and update your W-4. Do it once a year. Do it any time your income changes by more than a few thousand dollars. Our reader, if they’d done this mid-year, would have caught a meaningful shortfall before it turned into an April surprise.

That Side Gig Has Its Own Tax, and Nobody Withheld for It

Back to our reader. Say a chunk of that new income came from freelance design work paid through 1099s.

On the W-2 side, Social Security and Medicare get taken out automatically, and the employer covers half. On the 1099 side, you’re both the employee and the employer. That’s self-employment tax, a combined Social Security and Medicare levy that sits on top of regular income tax.

On a meaningful chunk of net freelance income, that self-employment layer alone can run well into four figures. Add federal income tax at their bracket and it’s easy for a side hustle to generate a bill that shows up nowhere on any pay stub. The IRS wants that money in quarterly installments during the year, not in one lump sum next April.

Two habits keep this from spiraling:

• Sweep a fixed percentage. Every time a client pays you, move a healthy slice of it into a separate savings account. Pretend that money was never yours. When quarterly deadlines hit in April, June, September, and January, the cash is already there.
• Track deductions as you go. Software subscriptions, a portion of your phone bill, mileage to client meetings, the home office. Waiting until March to reconstruct a year of expenses from memory is how people leave real money on the table.

The 401(k) Is the Best Lever You’re Not Pulling

Here’s where the story gets more optimistic. Extra income creates extra tax. It also creates extra room to move money into places the tax code rewards. For our reader, the single most powerful lever is the workplace retirement plan.

The IRS announced that employees can contribute up to $24,500 to a 401(k) in 2026, and up to $7,500 to an IRA. Every pre-tax dollar you shift into a traditional 401(k) lowers this year’s taxable income by that same dollar. If our reader bumped their contribution rate up by several percentage points, they’d shift thousands of dollars out of taxable income and into their own future.

That’s not a trick. That’s the deal Congress wrote. The people who build real wealth in their 30s aren’t the ones with the biggest paychecks. They’re the ones who noticed the levers and pulled them earlier than everyone else.

If You Rent, Skim This. If You Own, Read It Twice

Now suppose our reader bought a condo last year in a state with real income and property taxes. California, New York, New Jersey, Illinois: pick your flavor.

Suddenly they’ve got mortgage interest, property tax bills, and state income tax withholding all stacking up on the itemized side of the ledger.

For years, the cap on the state and local tax deduction made itemizing feel pointless for most young homeowners. That changed. The SALT cap jumped from $10,000 to $40,000 starting in 2025 and ticks up slightly each year through 2029.

For someone with a meaningful state income tax bill and a real property tax bill on top, that cap used to leave real money stranded. Now it doesn’t.

This does not mean everyone should itemize. The standard deduction is still higher for a lot of filers. But if you’re a homeowner in a high-tax state and you’ve been on autopilot since 2018, this is the year to actually run the numbers side by side. Don’t take the standard deduction because you always have.

When to Just Hire Someone

Our reader has now got a W-2, a 1099, quarterly estimated payments, a mortgage, a state return, and a 401(k) contribution they may want to increase before December 31. This is the moment where doing it yourself in TurboTax stops being a badge of frugality and starts being a way to overpay by hundreds or thousands of dollars.\

You don’t need a full-time accountant. You need one conversation, once a year, with someone who does this for a living. A decent tax pro will find deductions you didn’t know existed, tell you whether an S-corp election makes sense for the side income, and flag anything about your state return that a national software package handles poorly. In California, for example, a firm like Robert Hall & Associates builds strategy around the state’s specific rules, which national tools tend to treat as an afterthought.

The rough test: if your return this year involves any two of the items on the list below, get help.

• Self-employment income. Even a few thousand dollars in 1099 work changes the shape of the return.
• A move between states. Two part-year returns, two sets of rules, one very confused piece of software.
• A home purchase or sale. Closing documents contain deductions people routinely miss.
• Equity compensation. RSUs, ISOs, and ESPPs each come with their own tax landmines.
• A significant income jump. New brackets, new phase-outs for credits you used to claim, and often a first exposure to estimated taxes.

One Afternoon Now Beats a Panic in April

Back to the reader we started with. If they update their W-4 tonight, open a savings bucket for the freelance money, and nudge their 401(k) contribution up by a couple of percentage points before the last paycheck of the year, they’ve rewritten their April outcome.

No new income needed. No hustle. Just an afternoon of paying attention.

Making more money is the goal. Keeping more of it is a separate skill. Nobody teaches it in school, and nobody at your job is going to knock on your desk to remind you. But the levers are all there, sitting in plain sight, waiting for the version of you that decides this is the year to pull them.

Photo by Markus Winkler: Unsplash