What to pay the IRS by January 15 — from your own numbers
Drop your 2026 freelance income and expenses. Quartersafe works out your federal tax, the safe-harbor target that avoids the underpayment penalty, each quarter's required installment by the regular and the annualized (Schedule AI) method, and what's left to pay for the fourth quarter. It runs in your browser; nothing is uploaded.
How it works
- Drop your 2026 income and expenses (CSV or Excel) — or try the sample, or download the template.
- Enter last year's tax and AGI from your 2025 Form 1040, plus any W-2 wages and withholding.
- Read the January 15 number and the checks, then pay through IRS Direct Pay or EFTPS. With Pro, keep the full Schedule AI worksheet for Form 2210.
Why Quartersafe
For freelancers, 1099 contractors and sole proprietors who pay their own federal tax four times a year and want to know what to send by January 15 — without a $399/year app.
From the export you already have
A bank, Stripe, PayPal or bookkeeping export — any CSV or Excel with a date and an amount. IRS payments (USATAXPYMT, Direct Pay, EFTPS) are spotted and counted; transfers and draws are left out.
The safe harbor, applied
Pay the smaller of 90% of this year's tax or 100% of last year's (110% if last year's AGI was over $150,000) and there's no underpayment penalty. Quartersafe works out which one is lower for you.
The annualized method too
If most of your income came late in the year, Form 2210 Schedule AI can shrink the earlier installments. Quartersafe runs both methods and tells you which costs less.
2026 federal tax, worked out
Self-employment tax on 92.35% of net profit with the $184,500 wage base, the half-SE deduction, the 20% QBI deduction, the 2026 brackets and standard deduction, and Additional Medicare.
Checks before you pay
Last January's payment counted for the wrong year, a missed installment, a duplicate payout, a transfer read as income, rows from 2025 — flagged before you send money.
Print or export
Print the worksheet, or with Pro get the full Schedule AI worksheet, an Excel workbook, a Schedule AI CSV and every transaction as it was treated.
Simple pricing
Free for the estimate, the safe harbor, both methods and every check. Pro for the full Schedule AI worksheet and the exports.
Free
- Any number of rows
- Safe harbor, both methods, the Jan 15 payment and every check
- Schedule AI period 1 line by line, with a footer
- No signup, nothing uploaded
7-day pass
- 7 days of Pro, no subscription
- Full Schedule AI worksheet, no footer
- Excel workbook, Schedule AI and transactions CSVs
- For the January 15 payment or filing season
Pro Yearly Best value
- Everything in Pro
- All four 2027 due dates and the Form 2210 question
- Costs less than 6 months of monthly
Prices in USD. Secure checkout and sales tax handled by our payment partner. Already bought? Enter your license key.
Tools & guides
- Estimated tax calculator for the self-employed
- Form 2210 Schedule AI, worked out from your transactions
- Q4 Estimated Tax: What to Pay by January 15, 2027
- The Estimated Tax Safe Harbor: 90%, 100% and the 110% Rule
- The Annualized Income Installment Method, Explained
- A lighter alternative to Keeper for quarterly taxes
FAQ
What does Quartersafe do?
It reads your 2026 business income and expenses, works out your 2026 federal tax (self-employment tax and income tax), the safe-harbor amount that avoids an underpayment penalty, and the required installment for each quarter under both the regular method and the annualized income installment method (Form 2210 Schedule AI). Then it subtracts what you've paid and shows what to pay by January 15, 2027. It doesn't pay or file anything.
Is my data uploaded?
No. Your file is read by JavaScript in your browser tab and never sent to us or anyone else. Transactions aren't stored, so closing the tab clears them. Settings can be saved in this browser.
What's the safe harbor?
From Form 1040-ES and the Form 2210 instructions: you generally won't owe an underpayment penalty if, on time each quarter, you pay at least the smaller of 90% of your 2026 tax or 100% of the tax on your 2025 return — 110% if your 2025 adjusted gross income was over $150,000 ($75,000 if married filing separately). You also owe no penalty if your 2026 tax minus withholding is under $1,000.
When are 2026 estimated payments due?
April 15, June 15 and September 15, 2026, and January 15, 2027. You can skip the January payment if you file your 2026 return and pay all the tax due by February 1, 2027.
What is the annualized income installment method?
If your income was uneven — say a slow spring and a busy fall — you can work out each required installment from the income you'd actually earned by the end of each period (March 31, May 31, August 31, December 31) using Form 2210 Schedule AI. That can lower or remove the penalty for the early quarters. Quartersafe runs it for you and compares it with the regular 25%-a-quarter method.
Which files can I use?
CSV, tab-separated or Excel with a date and an amount on each row — positive for income, negative for expenses — or separate income and expense columns. A description and category are optional and help spot IRS payments and transfers. Download the template to see the layout.
What's free?
Importing any number of rows, the tax estimate, the safe harbor, both methods' installments, what to pay by January 15, and every check, plus the first Schedule AI period line by line on screen and in print (with a footer). Pro shows and prints the full Schedule AI worksheet without the footer and exports the Excel workbook, a Schedule AI CSV and the categorized transactions CSV.
What isn't covered?
State estimated tax, capital gains and qualified dividend rates, tax credits, itemized deductions, other taxes such as the net investment income tax, the qualifying-surviving-spouse status (use married filing jointly, which shares its tables), and farmers' and fishermen's rules. The QBI deduction is left out above the income threshold where its limits begin.
Is this tax advice?
No. Quartersafe applies Form 1040-ES and Form 2210 (with Schedule AI) to the data you provide. Ask your tax adviser what applies to you.