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Next federal deadline  Sep 15  in 2 days

Annualized estimates for the whole book, not just the clients worth the hours

Each one comes with the payment, the Form 2210 Schedule AI, and the filled 1040-ES vouchers.

Run one client's numbers See pricing

Free on a single return. No card.

The same authorities you already work from

Publication 505 Form 1040-ES Form 2210 Schedule AI

Built for the quarterly crunch. It replaces the spreadsheet, not your judgment.

Direct worksheet entry

You know what belongs in each box. Worksheet mode is a straight entry grid, no interview and no hand-holding, per client and per quarter.

Wages

$84,000.00

Schedule C net

$120,000.00

Withholding YTD

$9,200.00

2025 total tax

$31,400.00

Sample entries.

Client-ready deliverables

Each calculation produces the quarterly PDF report and filled 1040-ES vouchers. Send them as they are, or attach them to your letter.

PDF

Q3 report · Chen Household

Both methods, recommended payment, figures behind them

Ready
PDF

1040-ES voucher · Chen Household

Filled for Q3, ready to mail with the check

Ready

The Schedule AI package, produced

Fluctuating-income clients deserve the annualized method, and the 2210 Schedule AI work is why they rarely get it. Here it falls out of the same calculation.

Form 2210

Generated

Schedule AI, all four periods

Generated

Entry sheet for the preparer

Generated

Both methods, compared per client

Safe harbor and annualized income are computed on the same figures every quarter, with the lower penalty-free payment recommended. The comparison you build by hand, standing.

Safe harbor

110% of prior-year tax

$8,760.00

Annualized income Selected

Schedule AI, four periods

$6,412.00

Sample, Alvarez Q3.

Audit every line before you sign off. The math is shown, not summarized.

Both methods are computed side by side down to the installment, so the recommendation is checkable against Publication 505 instead of taken on faith. Your review happens once, not every quarter.

Annual constants are audited against the IRS source documents and pinned by automated tests. Tax logic reviewed by Steven Wu, CPA, formerly of PwC. Meet the team

Run one client's numbers

Alvarez, M. · 2026 worksheet

S-corp · annualized income · sample

Owner W-2 wages$96,000.00
Pass-through income (K-1), annualized$118,000.00
Federal income tax$38,942.00
Withholding to date−$14,800.00
Required annual payment$35,048.00
Q3 installment Due Sep 15$6,412.00

Sample calculation. Every figure expands to its source line.

2

Publication 505 methods computed per client, per quarter

4

Installment periods handled, Schedule AI included

1

Dashboard for the whole book, statuses at a glance

0

SSNs stored, ever. Voucher SSNs are collected per download and discarded

What practitioners ask first.

What does it cost per client?

Nothing per client. Professional plans are flat tiers sized by client volume, billed quarterly or annually. The calculation engine is identical on every tier, so a bigger plan buys capacity, never a better calculator. Details are on the pricing page.

Is there a client-ready deliverable?

Yes. Each calculation produces a clean quarterly PDF report with both methods and the recommended payment, plus filled 1040-ES vouchers. You send them as they are, or attach them to your own letter.

Can I audit the math behind the number?

Every line is visible. Both Publication 505 methods are computed side by side, the worksheet shows each figure down to the installment, and the annual constants are audited against IRS source documents and pinned by automated tests. Nothing asks to be trusted blind.

How is client data handled?

You type dollar amounts. Nothing connects to client accounts or books, and SSNs are never stored or logged. A voucher download collects the SSN fresh each time, fills the PDF, and discards it.

Here for your own estimates? You get the same calculations, set up for how you work.

Individuals

Freelancers, contractors, and anyone with income nobody withholds for. Plain questions, rough numbers, and the payment that keeps you penalty-free.

EstimatedTax.com for individuals

Business owners

Seasonal and project income sized to the quarter that earned it, with the annualized method and the Schedule AI paperwork handled.

EstimatedTax.com for businesses

Stop re-reviewing the same Excel formulas every quarter. Review the engine once, then put the hours where they bill.

Run one client's numbers See pricing

Free on a single return. No card, no SSN, no password.