1099tax.app
Tax guides
Plain-English explainers for the 2026 tax year, each linked to the calculator that fits.
These guides explain the tax rules behind our calculators in plain English. Each one covers a question that freelancers, founders and employees with equity pay often get wrong: when to pay, which forms to expect, what you can deduct, how to set up a business, which state can tax you, and how stock compensation is taxed.
Every guide is written for the 2026 tax year, cites the official IRS or state sources it relies on, and links to the calculator that turns the rules into a number for your situation. Start with the guide that matches your question, then run the linked tool with your own figures.
Quarterly Estimated Taxes for Freelancers (2026)
Who must pay 2026 estimated taxes, the four due dates, the 90%/100%/110% safe harbors and how to pay, explained for freelancers.
Who it’s for: freelancers, contractors, gig workers and side-business owners with no withholding on some of their income, especially in their first year of self-employment.
Read guide1099-NEC vs 1099-K: 2026 Thresholds Explained
The new $2,000 Form 1099-NEC threshold, the restored $20,000 / 200-transaction 1099-K rule, and how to report both without double-counting.
Who it’s for: anyone paid by clients, marketplaces, payment apps or card processors who receives one or more 1099 forms, or expects to, and wants their return to match them.
Read guideHome Office Deduction: Simplified vs Regular Method
Who qualifies for the home office deduction, the $5-per-square-foot simplified method vs Form 8829, with a worked example.
Who it’s for: self-employed people who work from home and want to know whether they qualify and which method gives the larger, simpler deduction.
Read guideSole Prop vs LLC vs S-Corp vs C-Corp: How to Choose
How legal structure and tax classification differ, and when a sole proprietorship, LLC, S-Corp election or C-Corp makes sense in 2026.
Who it’s for: new business owners deciding how to set up, and growing sole proprietors or LLC owners wondering whether an S-Corp election or a corporation now makes sense.
Read guideState Tax Residency When You Move
Domicile, statutory residency and part-year returns explained, with New York and California rules and steps that support a real move.
Who it’s for: anyone moving between states, especially remote workers and people leaving a high-tax state, who needs to know when the old state stops taxing them.
Read guideRSU, ESPP and Stock Option Taxes in Plain English
When RSUs, ESPP shares, ISOs and NSOs are taxed, the 2026 AMT figures, the 83(b) election, and worked examples.
Who it’s for: employees paid partly in company stock, including RSUs, ESPP shares, ISOs or NSOs, who want to avoid withholding gaps and basis errors at tax time.
Read guideHow to use these guides
Read a guide first if you are unsure which rules apply to you, then use the matching calculator to estimate the amount. If your situation involves several of these topics at once, such as a move in the same year you start freelancing, read each relevant guide, because the rules interact.
The guides follow the same sources and review schedule as the calculators, described on our Methodology page. They are general information, not tax or legal advice, so check your own situation with a qualified professional before you file. If something looks wrong or out of date, please tell us through the Contact page.