A mid-year withholding checkup
How to check what your paychecks are withholding for 2026, what the estimator needs from you, and how a new W-4 fixes a refund or a balance that is too big.
Quick answers
- How do I check if enough tax is being withheld?
- Run the IRS Tax Withholding Estimator with your most recent pay stub, your spouse's stub if you file jointly, and last year's return. It reports what you are on track to withhold against what you are on track to owe.
- What do I do if my withholding is short for 2026?
- Give your employer a new Form W-4 and use Step 4(c), a flat extra amount taken from every paycheck. Withholding counts as paid evenly across the year, so it can still cover income that had none of its own.
- Why does a second job leave me owing money?
- Because each employer withholds as though its salary is your only income, so each applies the lower brackets to its own paycheck and the combined income lands in a higher band. Step 2 of the W-4 fixes it only if both jobs are accounted for.
A withholding checkup takes about twenty-five minutes with a pay stub and the IRS estimator, and it tells you whether this year's paychecks are on track for a small refund, a small balance, or a surprise. The middle of the year is when there is still time to change the answer.
| Standard deduction, single | $16,100 | Rev. Proc. 2025-32 §4.14(1) |
|---|---|---|
| Standard deduction, married filing jointly | $32,200 | Rev. Proc. 2025-32 §4.14(1) |
| Top of the 12% bracket, single | $50,400 | Rev. Proc. 2025-32 §4.01 |
| Top of the 12% bracket, married filing jointly | $100,800 | Rev. Proc. 2025-32 §4.01 |
Why check now
The numbers your employer withholds against move every year. For 2026 the standard deduction is $16,100 for a single filer and $32,200 on a joint return, both larger than the year before, and the brackets shifted up with them — the 12 percent band now runs to $50,400 for a single filer and $100,800 for a couple.
Payroll systems pick those changes up automatically, so nothing is broken. What they cannot pick up is anything about your life that payroll does not see, and a W-4 filled out years ago is still driving the calculation.
Checking in the middle of the year matters more than checking in November. A shortfall found now is spread over the remaining paychecks; the same shortfall found in December has to come out of one or two.
What breaks withholding
Withholding is built from the assumption that the job in front of it is the whole picture. Anything that changes the picture is worth a check:
- Marriage, divorce, or the death of a spouse.
- A child born, adopted, or aged out of the child tax credit.
- A second job, a spouse starting work, or either of you stopping.
- Self-employment, freelance work, or rental income arriving alongside the W-2.
- A raise, a bonus, or equity vesting — bonuses are often withheld at a flat supplemental rate that does not match your actual bracket.
- Starting Social Security, or beginning withdrawals from a retirement account.
The estimator, and what to have ready
The IRS Tax Withholding Estimator projects the year and tells you what to put on a new W-4. It is only as good as what you feed it, so gather the inputs first.
- Your most recent pay stub, and your spouse's if you file jointly, showing federal tax withheld year to date.
- Your most recent federal return, which supplies the deductions and credits you are likely to claim again.
- Records of income outside the paycheck: self-employment, gig work, interest, dividends, Social Security.
- An idea of whether you will itemize this year or take the standard deduction.
The tool produces a filled-in Form W-4, or a Form W-4P if the income is a pension or annuity, which you hand to the employer or the payer. It is not built for nonresident filers; the IRS points them to Notice 1392 instead.
How to change it
Give your employer a new Form W-4 whenever the answer changes. There is no season for it and no limit on how often.
The line that does the most work is Step 4(c), extra withholding: a flat dollar amount taken from every paycheck on top of the normal calculation. It is the cleanest way to cover something payroll knows nothing about — a side business, investment income, a spouse's shortfall — because it is a number you control directly rather than a proxy dependent count.
Step 4(a) does the same job from the other direction by adding expected other income to the calculation. Either works. Extra withholding is easier to reason about, and easier to turn off.
The two-earner trap
Two jobs in a household is where withholding goes wrong most often. Each employer withholds as though its salary is the only income, so each applies the lower brackets to its own paycheck, and the combined income lands in a higher band than either calculation assumed.
The W-4 handles this in Step 2, and it only works if both jobs are accounted for — through the checkbox on both forms when the two salaries are similar, or through the estimator when they are not. The same trap catches a single person holding two jobs at once.
Retirement income
Pensions and annuities withhold on Form W-4P, and periodic payments default to a calculation that may have nothing to do with your actual return. IRA and retirement plan distributions have their own election on Form W-4R. Retirees with several income streams and no employer in the picture are the group most likely to find a balance due in April.
What a good result looks like
The target is a small refund or a small balance. A large refund is a loan you made without interest and could have had in each paycheck; a large balance is a bill you have to find money for, and past a certain size it brings an underpayment penalty with it. Run the checkup, change the W-4 if the projection is off, then check again in January when the new year's numbers take effect.