Quarterly Tax System · 2026 · 7-File Bundle

Pay quarterly taxes without the IRS penalty.

A spreadsheet, a 15-page survival guide, an IRS penalty abatement letter, a 50-state cheat sheet, a CPA handoff checklist, and a calendar file with every deadline. One download. $17.

7 files Excel + Google Sheets + PDFs + .ics 7-day refund Instant download
Start HereDashboardSetupTax CalcQ. Pay
Annual tax picture
SE TAX
$6,019
FEDERAL
$2,622
STATE
$1,430
TOTAL OWED
$10,071
Quarterly progress — federal
Q1Apr 15 · paid$2,160██████████
Q2Jun 15 · partial$1,200██████████
Q3Sep 15 · upcoming$0██████████
Q4Jan 15 · upcoming$0██████████
.xlsx
.pdf
.ics
The cost of doing nothing

Skip your quarterly taxes, owe $400 to $800 extra. Every. Single. Year.

The IRS underpayment penalty isn't huge — but it isn't nothing. On a $15,000 tax bill, missing all four quarterly payments costs about $400–$800 in pure waste. It's not deductible. It doesn't reduce next year's bill. It's gone.

This bundle does two jobs: stops the penalty from landing again next April — and if it already landed last year, gives you the letter to ask the IRS for a refund. The penalty abatement letter alone is what a CPA would charge $200+ to write.
$400+
Typical IRS underpayment penalty per year you skip quarterlies — non-deductible and entirely avoidable.
2×
IRS safe-harbor rules. You only need to hit one to be penalty-proof. The bundle calculates both, side by side.
~5min
From file download to "you know your Q1 payment" — Setup tab takes about five minutes to fill in.
What's in the bundle

Seven files. Each one does a specific job.

Not a "bundle" in the lazy sense — every file targets a different moment in your quarterly tax year. The spreadsheet runs the math, the guide explains why, the letter is your insurance against last year's mistake, the cheat sheet is your map, the checklist is for your CPA meeting, and the calendar makes sure you never miss again.

File 1 · The engine

Quarterly Tax System Spreadsheet

9-tab workbook for Excel and Google Sheets. Dashboard view, full SE + federal + state tax math, Q1–Q4 payment tracker, both IRS safe-harbor tests, and three worked-out examples.

Standalone value: ~$15
File 2 · The reference

The Survival Guide

Plain-English explainer of every rule the spreadsheet applies — why quarterly taxes exist, the penalty math, both safe-harbor rules, state systems, where to actually pay, and what to do if you missed a quarter.

Standalone value: ~$10
File 3 · The refund

IRS Penalty Abatement Letter

If the underpayment penalty already hit you last year, the IRS First-Time Abatement program will refund it — if you have the right letter. This is that letter.

CPA charge to write this: $200+
File 4 · The map

50-State Cheat Sheet

Every state plus DC: top marginal rate, where to pay, which form, and the few states with non-standard quarterly rules. Stop googling four times a year.

Standalone value: ~$7
File 5 · The handoff

CPA Year-End Checklist

Printable one-pager. Tick boxes as you gather documents, hand the whole stack to your CPA in January. Plus the four questions you should always ask before leaving the meeting.

Standalone value: ~$7
File 6 · The reminders

Quarterly Deadlines Calendar

Drag into Apple Calendar, Google Calendar, or Outlook. All 2026 and 2027 deadlines with 7-day and 1-day reminder alarms built in. One drag, reminders set forever.

Standalone value: ~$5
How it works

Three steps. Five minutes to set up. Penalty-safe for the year.

1

Open the Setup tab.

Filing status, state, expected income, last year's tax. Federal brackets and SS wage base are editable for any year so you reuse the file every January.

2

Forecast your year.

Month-by-month projection across up to 6 income streams — gig + Airbnb + Etsy + freelance + W-2, whatever applies. The total feeds the Tax Calculator automatically.

3

Track payments.

Q1–Q4 targets appear with due dates. Log each payment as you make it. The status column turns green when on track, amber when partial, red when behind.

Who it's for

If you get a 1099, this is for you.

The math is the same whether you're a Dasher or a part-time freelancer. The spreadsheet handles every income type below in one file.

Gig drivers
DoorDash, Uber, Lyft, Instacart, Grubhub, Amazon Flex, TaskRabbit, Rover, Shipt.
Airbnb & STR hosts
Airbnb, Vrbo, Booking.com, Furnished Finder, Hipcamp, RV rentals — anywhere SE tax applies.
Resellers & Etsy
Etsy, eBay, Poshmark, Mercari, Shopify, vintage resellers, and 1099-K recipients.
Freelancers
Upwork, Fiverr, direct clients, consultants, agencies of one.
Creators
YouTube, Twitch, TikTok, Patreon, Substack, OnlyFans, podcasters.
W-2 + side hustle
Day job pays withholding, side hustle doesn't. Calculator factors both so you only pay on the difference.
The guarantee

If it doesn't pay for itself, neither do you.

Seven-day no-questions-asked refund through Gumroad. And the penalty abatement letter alone can refund $400+ from last year's tax bill — that's 23× the price of the bundle from one file.

Get the bundle — $17 →
Instant download · Excel + Google Sheets + 4 PDFs + .ics calendar file
Common questions

Things people actually ask before buying.

Will this work in Google Sheets, not just Excel?

Yes. Drag the .xlsx file into your Google Drive — Sheets converts it cleanly and every formula keeps working. Tested on Excel 2016+, Excel for Mac, Numbers (light styling differences), and Google Sheets.

I'm a first-year self-employed filer. Is this still useful?

Yes — it's actually most useful for first-year filers, because you don't know yet what your tax bill will be. The Tax Calculator estimates your full-year liability from your income forecast, and the safe-harbor logic protects you even when last-year data isn't available.

Does this replace my CPA?

No — and it's not trying to. This handles the math your CPA charges you for as a side note (quarterly calculations, payment tracking, safe-harbor checks). When you actually file in April, a CPA is still worth it for QBI optimization, audit risk, and complex situations. The CPA Handoff Checklist in the bundle is specifically about making that meeting cheaper and faster.

The penalty abatement letter — does this really work?

Yes, for qualifying taxpayers. The IRS First-Time Abatement (FTA) program is a real administrative waiver that's been around since 2001. Most people who qualify don't know it exists. The letter walks through the three qualification rules and uses the same language CPAs use when requesting FTA. Not legal advice — every situation differs, but the program itself is real and routine.

What if it doesn't fit my situation?

Gumroad's 7-day refund applies, no questions. Open the files, click around, decide if it works for you. If it doesn't, request the refund through Gumroad and the charge is reversed.

Why $17 and not free?

Free quarterly tax content is everywhere — including 15+ free guides on this site. What's not free is a complete system: a spreadsheet that does the math, a guide that explains it, a letter that recovers last year's penalty, and a calendar that prevents next year's. Charging $17 also funds the time to keep the spreadsheet updated each January when the IRS publishes new brackets.

Ready to stop overpaying?

One download. Penalty-free year.

Get the bundle — $17 →
Or first, try the free quarterly tax calculator to see what you'd owe.