The IRS issued more than 102 million tax refunds for the 2023 filing season, averaging $3,167 per return. Recipients generally treated the refund as a windfall — a bonus from the government, evidence that they had managed their taxes well. It is none of those things. A refund is the return of money you overpaid throughout the year, held interest-free by the Treasury for up to 15 months. A $3,167 refund represents roughly $263 per month of excess withholding that could have been in your paycheck, paying down debt or earning investment returns. Treating a refund as a victory is treating an interest-free loan to the IRS as a savings strategy.
What a refund actually is
A tax refund is the difference between the total tax you paid during the year (through employer withholding and estimated payments) and the total tax you actually owed. Withholding is set on Form W-4, which your employer uses to calculate how much federal income tax to deduct from each paycheck. Set withholding too high, and you overpay all year, receiving the surplus as a refund the following spring. Set it correctly, and you owe or are owed a negligible amount at filing. The IRS does not pay interest on refunds for the period they hold your money — meaning every dollar of over-withholding is a dollar loaned to the Treasury at 0%.
The mechanics are simple but the psychology is fascinating. Workers describe refunds as "forced savings" — a way to set money aside without the discipline of monthly saving. The same workers would never describe loaning $3,000 to a bank at 0% interest for a year as a savings strategy, but that is exactly what they are doing. The difference is that the IRS makes the loan feel like a windfall by returning the money in a lump sum, which feels different from receiving $263 extra in each month's paycheck. The math is identical; the framing is opposite.
The history of withholding: how we got here
Federal income tax withholding is younger than most Americans assume. The modern income tax began in 1913 with the 16th Amendment, but for its first 30 years, taxpayers settled their full tax bill annually in March — a system that produced massive underpayment, late payments, and constant Treasury cash-flow problems. Withholding at the source arrived in 1943 with the Current Tax Payment Act, signed by President Roosevelt as a wartime measure. The rationale was not convenience for taxpayers but cash-flow certainty for the Treasury: the government needed steady monthly revenue to fund the war effort, not annual lump sums.
The intellectual architect was Beardsley Ruml, treasurer of Macy's and an advisor to the Roosevelt Treasury. Ruml had observed that Macy's customers paid their installment-plan bills more reliably when payments were small and frequent rather than large and annual. He proposed applying the same principle to federal taxation, and the Treasury adopted his framework essentially unchanged. The 1943 act required employers to withhold income tax from wages and remit it to the Treasury quarterly, producing the steady revenue stream that has funded the federal government ever since.
The system was designed to be slightly over-aggressive on withholding, because Treasury officials in 1943 worried that under-withholding would produce mass default at tax time. The default tables have retained that bias through every subsequent revision, including the 2020 redesign that replaced withholding allowances with direct dollar amounts. The W-4 instructions still nudge filers toward slight over-withholding, on the assumption that most taxpayers prefer a refund to a bill. For the 70 percent of filers who do get refunds, the system is working as designed — but the design serves the Treasury, not the taxpayer. Recognizing this history is the first step to choosing differently.
The opportunity cost of over-withholding
Every dollar over-withheld is a dollar not earning a return elsewhere. A $3,167 refund parked at 0% with the IRS for an average of 8 months represents roughly $89 in foregone interest at a 4% high-yield savings rate, or $221 in foregone returns at a 10% equity return. That is the floor of the cost; the ceiling is much higher if the over-withholding prevents you from paying down high-interest debt.
Consider a worker carrying $5,000 in credit card debt at 22% APR. A $3,000 annual refund means she overpaid the IRS by $250 monthly while paying roughly $92 monthly in credit card interest. If she had instead directed that $250 to credit card repayment each month, she would have eliminated the balance in 22 months instead of 30, saving roughly $410 in interest. The "forced savings" of the refund cost her $410 in additional interest paid to the credit card issuer.
Adjusting your W-4 the right way
The W-4 form was redesigned in 2020 to eliminate withholding allowances and replace them with direct dollar adjustments. The form walks you through five steps: personal information, multiple jobs or working spouse, dependents, other adjustments, and signature. Most workers complete only step 1 and step 5, which guarantees they default to single-with-zero-dependents withholding — usually too high for anyone with dependents, a mortgage, or significant deductions.
The IRS provides a Tax Withholding Estimator at IRS.gov/W4app that uses your actual prior-year tax return to recommend specific dollar amounts to enter on the W-4. Run it in late January after you have your prior-year W-2s and 1099s, then submit a new W-4 to your employer. The estimator accounts for multiple jobs, dependents, itemized deductions, and other income. It produces a target refund or balance due and tells you exactly what to put on lines 3, 4, and 4(c) of the new W-4.
Re-run the estimator annually, and any time your situation changes — marriage, divorce, new child, job change, significant raise, new mortgage, large bonus. Withholding that was correct last year is almost certainly wrong this year if anything material changed. The IRS adjusts tax brackets, standard deductions, and credits annually for inflation, so even a stable situation drifts slightly.
The 2026 tax brackets and standard deduction
For 2026, the standard deduction is projected to be approximately $15,000 for single filers and $30,000 for married filing jointly, after the IRS's annual inflation adjustment. The seven federal brackets remain at 10%, 12%, 22%, 24%, 32%, 35%, and 37%, with bracket widths adjusted upward for inflation. A single filer earning $75,000 in 2026 will owe roughly $9,800 in federal income tax after the standard deduction — about 13% effective rate, even though their marginal rate is 22%.
The standard deduction matters for withholding because it is the largest single reduction in taxable income for the majority of filers. Workers who do not adjust their W-4 to reflect the standard deduction typically over-withhold by $1,500 to $3,500 annually. The W-4 step 3 accounts for dependents, but the standard deduction is built into the default tables — meaning single filers with no dependents usually have approximately correct withholding, while married filers with children almost always over-withhold unless they complete step 3.
The ideal refund target: $0 to $500
The optimal refund is small. The IRS recommends aiming for a refund of $0 to $500 or a balance due of $0 to $500. The slight bias toward a small refund (rather than a small balance due) reflects two realities: the underpayment penalty risk discussed below, and the practical observation that most workers prefer a small windfall to a small bill. But $500 should be the ceiling, not the floor. A $3,000 refund is six times the upper bound of the recommended range.
For self-employed workers and others who pay quarterly estimated taxes, the target is similar. Each quarterly payment should approximate one-quarter of the prior year's total tax liability (the safe-harbor rule), with adjustments for income changes. Quarterly payments due April 15, June 15, September 15, and January 15 should each be roughly one-quarter of the expected annual liability. Large over-payments followed by a refund are the same interest-free loan to the IRS, just paid in installments.
Underpayment penalties: the risk on the other side
Under-withholding has its own cost. The IRS charges an underpayment penalty — effectively interest at the federal short-term rate plus 3 percentage points — if you owe more than $1,000 at filing AND your withholding and estimated payments were less than 90% of the current year's tax or 100% of the prior year's tax (110% if AGI over $150,000). For 2026, the federal short-term rate is likely to be in the 4% to 5% range, making the underpayment penalty roughly 7% to 8% annually on the shortfall.
The penalty is calculated on Form 2210 and assessed automatically. The 90% / 100% / 110% safe harbors are the critical thresholds: if you cover at least 100% of last year's tax liability (110% if high-income), you avoid the penalty even if you under-withhold significantly relative to this year's liability. This is the safe harbor high-income earners with variable compensation (bonuses, equity, self-employment) use to avoid penalties while keeping money invested through the year.
The penalty is not catastrophic — 7% to 8% on a $3,000 underpayment for an average of 8 months is about $140 — but it is avoidable. The right withholding strategy stays just inside the safe harbor while keeping refunds small. For most W-2 workers, targeting a $200 to $500 refund achieves both goals.
What the research says about refund psychology
Behavioral economists have studied the refund puzzle for decades, and the findings consistently confirm what practitioners observe: most taxpayers prefer refunds even when the math says they should not. The seminal 1995 study by Richard Thaler, published in the journal Marketing Science, framed the phenomenon using mental accounting theory. Taxpayers mentally categorize withholding as a loss already absorbed, while a refund registers as a gain. The asymmetry produces a preference for over-withholding that no amount of mathematical argument fully erodes. Subsequent surveys, including a 2018 study in the Journal of Consumer Affairs, found that 56 percent of U.S. taxpayers explicitly preferred a refund to a slightly higher paycheck, with the preference strongest among lower-income and younger filers.
A 2020 field experiment by Collins and colleagues, published in the Journal of Behavioral Economics, tested whether reframing could shift the preference. Researchers provided W-4 adjustment guidance to 1,200 workers, framing the choice in three different ways: as an interest-free loan, as foregone investment returns, or as a simple paycheck increase. The investment-returns framing produced the largest behavior change, with 38 percent of that group adjusting their W-4 versus 14 percent in the control group. The interest-free-loan framing was least effective, suggesting that abstract arguments about Treasury borrowing are less persuasive than concrete math about personal returns.
The research also helps explain why the W-4 redesign of 2020 did not reduce average refunds. The new form was supposed to make correct withholding easier, but average refunds actually rose slightly between 2019 and 2022. The form was not the problem; the bias toward over-withholding was. Default settings shape behavior more than form design, and the W-4's defaults nudge filers toward over-withholding. The taxpayer who wants a small refund must actively override the defaults, which most never do. The research is clear that information alone is insufficient; the default must be changed, and in its absence, the worker must override it deliberately.
State refund optimization: do not forget the second layer
Federal withholding is only half the picture for most workers. Forty-one U.S. states levy a broad-based income tax, and each operates its own withholding system that mirrors the federal W-4 in concept but varies in detail. State withholding forms often default to over-withholding even more aggressively than federal, partly because state tax brackets are narrower and partly because state refund mechanisms are slower. A worker who fixes the federal W-4 but ignores the state equivalent often sees only half the refund reduction they expected.
State-level mechanics vary widely. California uses Form DE 4, which has separate allowance lines for federal and state. New York uses Form IT-2104, which allows additional dollar-amount withholding reductions. Texas, Florida, Nevada, Washington, South Dakota, Wyoming, and Alaska have no state income tax, eliminating this layer entirely. A worker in a high-tax state like California or New York might see state refunds of $800 to $1,500 layered on top of federal refunds, doubling the over-withholding problem. Check your state's department of revenue website for the equivalent of the federal W-4 estimator.
The state-level opportunity cost is actually higher than the federal, because most state tax refunds are processed more slowly. The IRS typically issues refunds within 21 days of e-filing, but several states (California, Illinois, New York) routinely take 6 to 12 weeks during peak season. That extends the interest-free loan period substantially. A $1,000 California state refund held for an average of 11 months at 4 percent high-yield savings is another $37 in foregone interest, on top of the federal refund cost. The fix is the same: locate your state withholding form, use the state estimator if available, and submit an updated form to your employer.
Special situations: equity compensation and side income
Equity compensation is the single largest source of surprise tax bills for knowledge workers, and it is also a case where under-withholding is endemic. Restricted stock units (RSUs) vest and are taxed as ordinary income at vesting, but employers typically withhold only the statutory federal minimum of 22 percent (37 percent for vestings above $1 million). For a worker in the 32 or 35 percent marginal bracket, this guarantees under-withholding, producing a balance-due return and a potential underpayment penalty. The fix is to increase W-4 line 4(c) by an amount that covers the gap, calculated as (marginal rate minus 22 percent) times the vesting value, divided by remaining pay periods.
Employee stock purchase plans (ESPPs) are even more error-prone. The discount element is taxable as ordinary income in the year of purchase, but most employers do not withhold on it at all. A worker buying $25,000 of ESPP shares with a 15 percent discount generates $3,750 of ordinary income with zero withholding. If this happens repeatedly across multiple purchase periods, the year-end tax bill can be five figures. The cleanest solution is to sell a portion of the shares immediately at purchase to cover the tax, or to adjust W-4 line 4(a) to add the expected ESPP discount as additional income subject to withholding.
Self-employment and side income have their own complexities. Net self-employment income above $400 triggers both income tax and self-employment tax (the employer and employee halves of FICA, totaling 15.3 percent on the first $168,600 of 2025 net earnings). No employer withholds from this income, so quarterly estimated payments on Form 1040-ES are mandatory. The safe harbor of 100 percent of prior-year tax (110 percent for AGI above $150,000) is the simplest rule: pay that amount in four equal installments, and you will not owe a penalty even if your actual liability turns out higher. Workers with both W-2 and significant self-employment income often adjust W-4 line 4(c) to cover the self-employment tax rather than making separate quarterly payments, which is administratively simpler.
Year-end tax moves to right-size your refund
By early December, you have enough information to project your full-year tax liability with reasonable accuracy. Pull your most recent pay stub, total your year-to-date withholding, and estimate the remaining pay periods through December 31. Compare the projected total withholding to your projected tax liability. If you are on track for a large refund, you can submit a final W-4 adjustment for the last few pay periods, though the window is narrow. If you are on track for a large balance due, increasing withholding in December can prevent or reduce an underpayment penalty.
Several year-end moves affect the final tax bill. Contributing to a traditional IRA or 401(k) reduces taxable income (the 401(k) deadline is December 31; the IRA deadline is the April filing deadline). Bunching deductible expenses — making January's mortgage payment in December, prepaying property taxes if allowed under the SALT cap, scheduling an elective medical procedure — can push itemized deductions above the standard deduction for the current year. Charitable contributions are similarly bunchable, and donor-advised funds allow multi-year charitable bunching without losing the deduction timing.
Tax-loss harvesting in taxable investment accounts can offset up to $3,000 of ordinary income per year, with excess losses carrying forward indefinitely. If you have substantial unrealized losses in taxable positions, selling them before December 31 captures the deduction for the current year. Be careful of the wash-sale rule: repurchasing the same or substantially identical security within 30 days disallows the loss. The simplest workaround is to buy a similar but not identical fund — swapping one S&P 500 index for a total-market index, for example — to maintain market exposure without triggering the rule.
What to do with the extra paycheck money
Adjusting your W-4 to reduce a $3,000 refund to $300 puts about $225 per month back in your paycheck. Without a plan, that money disappears into lifestyle inflation. Set up an automatic transfer for the exact amount of the withholding reduction, dated for the day after each payday, directed to wherever it does the most good: high-interest debt first, then an emergency fund to three months of expenses, then tax-advantaged retirement contributions, then taxable investing. The automation is essential — money not automatically redirected tends to be money not saved.
The behavioral objection to this approach is the loss of the "forced savings" mechanism. The objection is valid for workers who genuinely will not save the money if it lands in their checking account. But the solution is not to overpay the IRS — it is to set up an automatic transfer to a savings or investment account on payday. The forced-savings benefit is replicated, the interest is captured by you instead of donated to the Treasury, and the discipline of setting up the transfer is a one-time cost rather than an annual tax bill.
Running the numbers yourself
The IRS Withholding Estimator at IRS.gov/W4app takes about 15 minutes with your most recent pay stub and prior-year tax return. The output is a specific W-4 to submit to your employer. Re-run it annually and after major life changes. Our Tax Refund Estimator complements the IRS tool by letting you model different withholding scenarios and project your refund or balance due before filing season arrives. The right target is a small refund or small balance due — not the four-figure windfall that the marketing of "tax season" has trained Americans to celebrate.