Estimated taxes for S corporation owners

An S corporation pays you two ways. A salary comes through payroll with tax withheld. The rest of the profit comes through on Schedule K-1 with nothing withheld. Every estimated tax problem an S corp owner has lives on the K-1 side, and the fix is often one line on a W-4 rather than four quarterly payments.

Your two streams of income

If you work in the business, you are its employee. The IRS requires the company to pay you reasonable compensation for that work before it makes any other payment to you. The salary runs through payroll as W-2 wages, with federal income tax, Social Security, and Medicare withheld.

The remaining profit passes through to you. An S corporation pays no federal income tax itself. It reports each shareholder's share of income, losses, deductions, and credits on Schedule K-1 (Form 1120-S), and you report that share on Schedule E of your Form 1040 at your own rates. Nothing is withheld from it.

Distributions are not the taxable event. You owe tax on your K-1 share whether the company paid it out or kept it as working capital. An owner who leaves $60,000 in the business to fund next year still owes this year's tax on it. The K-1 figure is what you have to cover, not the transfers to your personal account.

The K-1 share is income tax, not payroll tax

Your share of S corporation income is not self-employment income and is not subject to self-employment tax. The shareholder instructions for Schedule K-1 say so in one sentence. Social Security and Medicare were collected on your salary, and non-wage distributions carry no employment tax. That gap is why the reasonable compensation rule exists. The IRS can reclassify distributions as wages when the salary is too low for the work, and a thin salary next to a large distribution is the main audit exposure in this structure.

So for an owner who works in the business, the K-1 share adds income tax and nothing else. A shareholder who does not materially participate is in a different spot. That share is passive, and passive business income counts as net investment income. The 3.8% net investment income tax applies to it once modified AGI passes $200,000 for a single filer or $250,000 for a married couple filing jointly.

The withholding lever

This is the advantage over a sole proprietor or a partner. You are on payroll, so you can pay the tax on your K-1 share through withholding instead of quarterly payments. For the underpayment penalty, the IRS treats federal income tax withheld as paid in four equal parts on the four due dates unless you show otherwise. The date the money left a paycheck does not matter.

That rule turns Form W-4 into a payment tool. Enter an extra dollar amount in Step 4(c), and the company withholds it from every paycheck. Withholding added in December counts as one-fourth paid on each of the four quarterly due dates, April and June included. One W-4 change replaces four deadlines and the timing risk behind an underpayment penalty.

The limit is the size of the paycheck. Withholding cannot exceed gross pay, so a small salary next to a large profit share runs out of room. Start early in the year so the extra amount fits inside normal paychecks. If the salary cannot carry the whole figure, withhold what it can and send the rest as quarterly payments. A partner has no salary at all, so a partner covers the entire share with partnership K-1 estimated payments.

Safe harbor for S corp owners

You owe no penalty if your withholding and timely payments reach 90% of this year's tax or 100% of last year's total tax, whichever is smaller. If last year's adjusted gross income was over $150,000, the prior-year figure becomes 110%. The safe harbor rule is a fixed target from a return you already filed. For a growing company, last year's tax is smaller than this year's, so the prior-year figure is the lower target. The safe harbor removes the penalty only. The balance is still due in April.

When profit arrives unevenly

A business that earns most of its profit late in the year has a problem with the regular installment method. That method assumes a quarter of the year's income arrived in each period, so it charges you in April and June for profit you had not earned. The annualized income method sizes each installment to the profit earned by each cutoff date. Your K-1 does not exist until the company files Form 1120-S after year end, so you estimate your share from the books. Your ownership percentage times the profit and loss statement through each cutoff is the working figure.

The state side

Most states now let an S corporation elect to pay state income tax on the pass-through income itself. Where the company makes that election, your personal state estimated payments drop or disappear, and you claim a credit for the entity's payment on your state return. The election and the credit differ by state. Confirm yours before you change what you send. Our guide to state estimated taxes covers the personal side.

A worked example

Take a single filer with a $90,000 salary and a $120,000 K-1 share for 2026, with the standard deduction and no other income. Regular payroll withholding covers the tax on the salary, about $10,970. The K-1 share qualifies for the 20% qualified business income deduction, so $24,000 of it comes off and the other $96,000 is taxed in the 22% and 24% brackets. Total federal income tax comes to about $33,370, so the K-1 share adds about $22,400.

You can send that as four payments of about $5,600 on the quarterly due dates. Or you can add about $1,870 of extra withholding a month on the W-4. On a $7,500 monthly paycheck that is a quarter of gross pay, so starting in January matters. Wait until October and the three paychecks left cannot absorb it, and the rest goes out as quarterly payments.

Sources: IRS S corporations · IRS S corporation compensation · Shareholder's Instructions for Schedule K-1 (Form 1120-S) · Instructions for Form 2210 · IRS Publication 505