mathstub notion toolkit · $19
Year-End Tax Playbook
The dated decision calendar tech workers run from Oct 1 to Apr 15. Every IRS deadline that matters, the cost of missing each one, an ICS file you can import into your calendar in 30 seconds, and a 1-page brief that saves billable CPA time.
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Worked example
Catches the $1,400 4Q underpayment penalty before it lands
Most tech workers blow past the §6654 safe harbor by accident — bonus or vest checks in November, no W-4 4(c) adjustment. This Playbook flags it at Q3 (Sep 15) when there is still time to fix it via withholding, not penalty.
What’s inside
Six sections, each with worked math + a live Notion database + a deep-link to the matching free Mathstub calculator.
27-deadline calendar
IRS §, $ cost-of-missing per row
ICS export
Import all 27 to Google / Apple / Outlook
W-4 4(c) workbook
Shortfall ÷ pay-periods math, 3 scenarios
17-row tax-doc inventory
Every W-2 / 1099 / K-1 / 3921 / 3922
Scenario cookbook
8 recipes for the most-common situations
CPA brief
1-page printable, saves billable time
Why buyers trust this
Good fit if
- W-2 tech worker with at least one bonus or vest event per year
- Anyone who has been surprised at tax-filing time by a withholding shortfall
- High earners who want the dated checklist instead of "I will figure it out in March"
Not a good fit if
- Pure 1099 / self-employed (use a quarterly-only flow instead — partial overlap)
- You want tax-filing software (this is the calendar + brief, not Form 1040 prep)
Ready when you are.
30-second Notion import. Lifetime updates. Money-back guarantee.
Other templates in the toolkit
Affiliate disclosure — Mathstub earns from sales on this Mathstub-owned template. The free calculators stay free.