Guides (2026)
How the rules behind the calculators work, each checked against IRS and state sources.
Choosing a structure
Start here if you are still picking. These cover what each structure pays and who files what.
- LLC vs S corp: what is actually differentAn S corp is a tax election, and an LLC can make it. What changes compared with a default LLC, when the election pays and what it costs to run.
- How sole proprietors are taxedSchedule C, self-employment tax, the QBI deduction and four estimated payments a year. A worked 2026 example puts real numbers on each one.
- How a single-member LLC is taxedHow a single-member LLC is taxed in 2026: disregarded entity rules, Schedule C, self-employment tax, state LLC fees, the EIN and when it files differently.
- How a multi-member LLC is taxedTwo owners, one LLC, no election: you file Form 1065, send K-1s, pay members through guaranteed payments, owe SE tax, and maybe switch to an S corp.
- When a C corp makes senseA C corp pays a flat 21%, and dividends get taxed again. It can win when you keep profit in the company or qualify for QSBS. Watch the accumulated earnings tax.
Running an S corp
For owners who have elected S corp status or are about to. Most of the money questions sit here: your salary, payroll, health insurance and expenses.
- How to elect S corp status with Form 2553You elect S corp status by filing Form 2553. Who has to sign it, the 2 months and 15 days deadline, what to do if you're late, and state elections.
- How to set a reasonable salary for an S corp ownerThe IRS wants S corp owners to pay themselves a reasonable salary. What that means, what courts look at, and why the StructureCost default is a starting point.
- What payroll costs an S corp ownerPay yourself a salary from an S corp and you're running payroll. What employer taxes, FUTA, state unemployment and the quarterly forms cost in 2026.
- Health insurance for S corp owners (2% shareholders)How S corp owners deduct health insurance: premiums in W-2 box 1 but not boxes 3 and 5, the self-employed health insurance deduction and Notice 2008-1.
- Accountable plans for S corp ownersYour S corp can pay back your home office, phone and miles tax free, but only under an accountable plan. Here's what Reg. 1.62-2 asks for, with 2026 numbers.
- How to revoke an S corp electionTo end an S corp election you need shareholder consent and a short statement to the IRS. Then the timing, and a 5-year wait if you ever want it back.
Taxes through the year
Taxes that come due whatever the structure, and the deductions and plans that cut them.
- How self-employment tax worksFor 2026 it's 15.3% on 92.35% of profit, with Social Security capped at $184,500. You deduct half. High earners owe the 0.9% additional Medicare tax too.
- Quarterly estimated taxes for business ownersNo withholding on business profit means you pay tax four times a year. The 2026 dates, the 100% and 110% safe harbors, the penalty, and corporations.
- The QBI deduction (Section 199A) in 2026Up to 20% of pass-through business income comes off taxable income. Over $201,750 single or $403,500 joint, service business and W-2 wage limits apply. $400 minimum.
- Pass-through entity tax elections and the SALT capHow state PTET elections let S corps and partnerships deduct state income tax federally, which states offer one, and how the 2026 SALT cap changes the math.
- Solo 401(k) contributions by business structureHow much a one-person business can put in a solo 401(k) in 2026, why the employer part is 20% of net earnings or 25% of W-2 pay, and what a low salary costs.
Forming the business and paying yourself
The paperwork side: setting up the LLC, where to form it, state franchise taxes and how to take money out.
- How to form an LLCMost states follow the same order: articles of organization, a registered agent, an EIN, an operating agreement. Then a report every year. Real examples included.
- Forming your LLC in another stateA Wyoming LLC for a business run from San Diego still owes California $800 a year. Foreign registration, both states' fees, and when it pays off.
- State franchise taxes and other taxes on the business itselfSome states tax the company itself, profit or not. How it works in California, Texas, Delaware and Tennessee in 2026, plus the states that tax gross receipts.
- How to pay yourself from an LLC or S corpOwner's draw, guaranteed payments, salary and distributions: how single-member LLC, multi-member LLC and S corp owners take money out, and how each is taxed.