Estimated taxes
A planning estimate of the year's federal estimated tax, from the books, with every number's math shown. It is not tax advice: your accountant confirms the amounts before you pay. State estimates are a later phase. (Dated 2026-10-18; ADR-0200.)
What it figures
Open Estimated taxes. The return type comes from the company's tax profile (change it on the page):
- Schedule C (a sole proprietor or single-member LLC) and a partner's or S corporation shareholder's share on Schedule K-1: the owner's individual estimate, line by line as Form 1040-ES's worksheets: self-employment tax (92.35% of the profit; 2.9% Medicare and 12.4% social security up to the year's wage base, less wages already taxed; never on an S corporation share), half of it deducted, the standard deduction or your itemized figure, the tax rate schedule, credits, withholding.
- C corporation: 21% of the projected taxable income, as IRS Publication 542's worksheet (Form 1120-W is historical).
Income is the books' net income for the year to date annualized (× days in the year ÷ days so far), the year to date as it is, or a projection you enter, plus any book-to-tax adjustments (for example, the standard mileage deduction in place of vehicle costs).
Safe harbors. Enter last year's total tax: an owner's required payment is the smaller of 90% of this year's tax and 100% of last year's (110% when last year's AGI was over $150,000, $75,000 married filing separately). Nothing is required under $1,000 after withholding, or after a year with no tax. A corporation pays the smaller of this year's tax and last year's (a large corporation: last year's only for the first installment); nothing under $500.
Tax tables, rates and thresholds are data with their sources (Rev. Proc. 2024-40 and 2025-32, Form 1040-ES 2026, SSA). A year without tables is refused, never guessed. Not included: the alternative minimum tax, the additional Medicare and net investment income taxes, and the annualized installment method.
The four installments
Due April 15, June 15, September 15 and January 15 for individuals; the 15th of the 4th, 6th, 9th and 12th months for a corporation. A date on a weekend or a legal holiday (including DC Emancipation Day) moves to the next business day, and the page says why. Each quarter shows the installment, what is paid and what is left; an overpayment carries forward.
Save and recalculate saves the inputs and the schedule. The saved schedule is what reminders and your accountant's console use; when the books change, the page recalculates and tells you the saved one is older.
Paying
Pay through the IRS (Direct Pay, EFTPS or your IRS online account), then Record payment on the quarter: it posts an entry to the payment account (the owner's draw for an owner's estimate, or a tax account for a corporation) from the bank account you choose. If you paid from a personal account, tick paid from a personal account: it is recorded and nothing posts. Agents can propose a payment's entry (from the bank line, say); a person approves it. A wrong payment is voided with a reason (reverse its entry too).
Reminders and your accountant
With reminders on, the owner and CPA (verified addresses) get an email before a due date that still has something to pay (7 days before by default). Your accounting firm sees every client's next due date and who has not paid on Estimated taxes in its console, and in the client list's attention reasons (overdue, or due within two weeks).
Over the API and MCP
GET /v1/estimated-taxes?year= (every line with its math), POST /v1/estimated-taxes/plan, POST /v1/estimated-taxes/payments, GET /v1/firm/estimated-taxes. The inputs and voids are people's; agents read and propose payments.