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.
Self-employed & gig work
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.
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
Withdrawals, pensions, and Social Security withhold nothing by default. 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
Sold a business or had a big crypto year? Safe harbor and annualization keep a one-time spike 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.
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