Learn quarterly taxes
Plain-English guides to estimated taxes. No tax-form vocabulary required.
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The Safe Harbor Rule
Pay 100% or 110% of last year's tax and the IRS cannot penalize you. The exact thresholds, the fine print, and when not to use it.
Read the guide →Self-Employed Quarterly Taxes
New to 1099 income? Whether you owe quarterly payments, how much, and how to make your first one.
Read the guide →The basics
The Annualized Income Method
How the IRS method for uneven income works, period by period, and the Schedule AI paperwork it requires.
Safe Harbor vs. Annualized Income
The two IRS methods for quarterly estimated taxes, how each one works, and how to pick the right one for your income.
The Underpayment Penalty
What triggers it, how the IRS calculates it, and the three ways to never pay it.
How to Lower an Underpayment Penalty
The IRS figure assumes even income. Four ways to bring it down, what to file, and what to do with a CP30 notice.
How Much to Set Aside for Taxes
The 25 to 30% rule, where it comes from, when it is wrong, and how to find your exact number.
State Estimated Taxes
Most income-tax states want their own quarterly payments, with different thresholds and schedules.
What Is Form 2210?
The underpayment penalty form. What Part I, Part II, and Part III do, and when filing it lowers the bill.
Form 2210 Schedule AI, Line by Line
How to fill out the annualized income schedule that resizes each installment to the income you actually had.
IRS Underpayment Penalty Rate
The current rate the IRS charges on underpaid estimated tax, every quarter back to 2022, and how the math works.
What Is Form 1040-ES?
The IRS estimated tax package. What the worksheet and the four vouchers do, and which parts you can skip.
Self-employed & business owners
First Year of Self-Employment
What changes when the paycheck stops, and the prior-year rule that makes year one penalty-proof.
DoorDash Taxes
What the 1099-NEC covers, the mileage deduction, and when dashing income needs quarterly payments.
Uber and Lyft Driver Taxes
Why the 1099-K shows more than you were paid, the fees and miles to deduct, and the quarterly rules.
Self-Employment Tax Explained
The 15.3% rate, how to calculate it on your own profit, the wage base, and the deduction for half of it.
S Corporation Owners
A W-2 salary plus a K-1 share of profit. How extra payroll withholding can cover the unwithheld part.
Partnership and LLC K-1 Income
Your share is taxed with nothing withheld and the K-1 arrives after every deadline. How partners set payments.
Investments
Capital Gains
When investment gains require quarterly payments, the rates that apply, and how to stay penalty-free.
Rental Income
Profit after depreciation, the passive loss rules, and when landlords owe quarterly payments.
Crypto
Swaps count as sales and exchanges withhold nothing. What is taxable and when quarterly payments apply.
RSU Withholding
Vests are withheld at a flat 22% while most equity holders sit in higher brackets. How the gap builds and how to close it.
How Bonuses Are Taxed
There is no special bonus tax, just flat 22% withholding that over-collects for some and under-collects for high earners.
Retirement & life events
Estimated Taxes in Retirement
Social Security withholds nothing by default, and IRA and pension defaults miss your other income. The safe harbor number, and the December RMD strategy.
Taxes After Selling Your Home
The $250,000/$500,000 exclusion, when gain is taxable, and how to pay on a mid-year sale without a penalty.
Estimated Taxes on a Windfall
A business sale or a large crypto gain is a one-time spike. Safe harbor and annualization keep it penalty-free.
Where to file
Estimated Tax Due Dates
All four IRS deadlines, the months each payment covers, and what happens if you miss one.
Where to Mail Estimated Payments
The IRS box for your state, plus the checklist for mailing a 1040-ES voucher and check.
Where to Mail Form 1040
The right IRS address for your paper tax return, with or without a payment enclosed.
How to Pay Estimated Taxes
Direct Pay, Online Account, EFTPS, card, and check compared. Fees, setup time, and what to select.
California Estimated Tax Payments
Where to pay, the 30/40/0/30 installment schedule, the $500 threshold, and the safe harbor rules that differ from federal.
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